ﻭ ﻤﻨﻪ F ( x ) = 1 (ln( x ) )4 4 = f ( x ) ﻭI=]1 ;+¥[ 1 /9 x. ln( x ) =f ( x ) ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ. I ﻟﻴﻜﻥ x ﻋﻨﺼﺭﺍ ﻤﻥ I ﻋﻨﺩﺌﺫ: 1 1 x = 2 . x ln( x ) 2 ln( x ) ﻭ ﻤﻨﻪ F ( x ) = 2 ln( x ) = f ( x ) ﻭI=]1 ;+¥[ 1 /10 x. ln( x ) ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ. I ﻟﻴﻜﻥ x ﻋﻨﺼﺭﺍ ﻤﻥ I ﻋﻨﺩﺌﺫ: 1 f ( x ) = x ln( x ) ﻭ ﻤﻨﻪ ) F ( x ) = ln(ln( x )) ﻷﻥ(ln(x)>0 ﺍﻟﺘﻤﺭﻴﻥ :10 ﻟﺩﻴﻨﺎ fﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭ ﺭf ( x ) = 6 x 2 + 5 x : 2 x + 1 /1 ﺘﻌﻴﻴﻥ ﺍﻟﻤﺠﻤﻭﻋﺔ ،D ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ :f ﻟﺩﻴﻨﺎD={x,xÎÂ :2x+1¹0} : = R - { - 1 } 2
/ﺇﻴﺠﺎﺩ ﺃﻋﺩﺍﺩ ﺤﻘﻴﻘﻴﺔ c، b ، a ﺒﺤﻴﺙ ﻤﻥ ﺃﺠل ﻜل ﻋﻨﺼﺭ x ﻤﻥ ﺍﻟﻤﺠﻤﻭﻋﺔ D ﻴﻜﻭﻥ2 f (x ) = ax + b + c : 2 x + 1 ﻟﻴﻜﻥ x ﻋﻨﺼﺭﺍ ﻤﻥ: D f ( x ) = 6 x 2 + 3 x - 3 x + 5 x ﻟﺩﻴﻨﺎ : 2 x + 1 = 3x ( 2 x +1) + 2 x 2 x + 1 = 3x ( 2 x +1) + 2 x +1 -1 2 x + 1 ﺃﻱ ﺃﻥf (x ) = 3 x + 1 - 1 : 2 x + 1 ﻭ ﻤﻨﻪ ﻴﻜﻔﻲ ﺃﺨﺫ a=3 : ﻭ b=5 ﻭ.c=1 * ﻜﺎﻥ ﺒﺎﻹﻤﻜﺎﻥ ﺇﺠﺭﺍﺀ ﺍﻟﻘﺴﻤﺔ ﺍﻹﻗﻠﻴﺩﻴﺔ ﻟـ (6x 2+ 5x) ﻋﻠﻰ. (2x+1) - 1.]¥ ; [ /3 ﺘﻌﻴﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ fﻋﻠﻰ ﺍﻟﻤﺠﺎل 2 ]¥ ; [ ﺤﻴﺙ k ﺜﺎﺒﺕ ﻤﻥ - . 1 ﻨﺴﻤﻲ Fk ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ fﻋﻠﻰ 2 - 1.]¥ ; [ ﻤﻊ ﺍﻟﻤﻼﺤﻅﺔ ﺃﻥ ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ 2 1 ﻟﻴﻜﻥ x ﻋﻨﺼﺭﺍ ﻤﻥ ، ]¥ ; [ - ﻋﻨﺩﺌﺫ: 2 f (x ) = 3 x +1 - 1 2 x + 1 = 3x +1 - 1 . - 2 2 - 2 x -1 Fk ( x ) = 3 x 2 + x - 1 ln( -2 x - 1) + k ﻤﻨﻪ ﻭ 2 2
ﺍﻟﺘﻤﺭﻴﻥ :11 ﺤﺴﺎﺏ ﺍﻟﺘﻜﺎﻤل ﻤﻥ ﺍﻟﺘﻜﺎﻤﻼﺕ ﺍﻟﻤﻌﻁﺎﺓ : e 1 òI 1 = dx / 1 x 1 I 1 e =1 dx e ﻟﺩﻴﻨﺎ : x = ò [ln( x )]1 1 òI 2 e 2 x 2 + x + 1d x /2 x 3 = e= òI2 e 2 x 2 + x +1d x = [ln( x ) - 1 - 1 ] e 2 ﻟﺩﻴﻨﺎ : e x 3 x 2 x 2 e I2 = 2 - 1 1 1 1 - -1 + + 2e 2 ﺃﻱ : e 2 2 e 4 e = 1 - 1 - 1 + 1 2 e 4 2 e 2 e 1 x òI = dx /3 3 x 2 + 1 0 I 3 = 1 x =dx [ 1 ln( x 2 + 1) ]1 0 = 1 ln( 2 ) ò x 2 1 2 2 ﻟﺩﻴﻨﺎ : + 0 ﺍﻟﺘﻤﺭﻴﻥ :12 fﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ﺍﻟﻤﺠﺎل ]0 ;+¥[ ﺒﺎﻟﺩﺴﺘﻭﺭf ( x ) = x ln( x ) - x : /1 ﺘﻌﻴﻴﻥ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ : f ﻟﻴﻜﻥ x ﻋﻨﺼﺭﺍ ﻤﻥ]0 ;+¥[ ﻟﺩﻴﻨﺎf ¢ (x ) = 1 . ln( x ) + x. 1 -1 : x = ln( x)
/2 ﺘﻌﻴﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ ln ﻋﻠﻰ ﺍﻟﻤﺠﺎل. ]0 ;+¥[ ﺒﺎﻻﺴﺘﻔﺎﺩﺓ ﻤﻥ ﺍﻟﻔﺭﻉ ﺍﻷﻭل ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ ln ﻋﻠﻰ ]0 ;+¥[ ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ : ® x ln( x ) - x + k ﺤﻴﺙ xk ﺜﺎﺒﺕ ﺤﻘﻴﻘﻲ. ﺍﻟﺘﻤﺭﻴﻥ :13 ﻨﻔﺱ ﻓﻜﺭﺓ ﺍﻟﺘﻤﺭﻴﻥ 12 ﻤﻊ ﺍﻟﻤﻼﺤﻅﺔ ﺃﻨﻪ ﻤﻥ ﺃﺠل ﻜل x ﻤﻥ ]1 ;+¥[ æ x + 1 ö ln( x + 1) - ln( x + 2 ) = ln ç ﻟﺩﻴﻨﺎ÷ : è x + 2 ø ﺍﻟﺘﻤﺭﻴﻥ :14 ﺤﺴﺎﺏ ﻜل ﻨﻬﺎﻴﺔ ﻤﻥ ﺍﻟﻨﻬﺎﻴﺎﺕ ﺍﻟﻤﻌﻁﺎﺓ:ﻓﻲ ﻜل ﺤﺎﻟﺔ ﻤﻥ ﺍﻟﺤﺎﻻﺕ ﺍﻟﺘﺎﻟﻴﺔ ﻨﺴﻤﻲ f(x) ﺍﻟﻌﺒﺎﺭﺓ ﺍﻟﻤﻌﻁﺎﺓ ) ﺍﻟﺘﻲ ﻁﻠﺏ ﺤﺴﺎﺏ ﻨﻬﺎﻴﺘﻬ ﺎ(. li-m ¥ çèçæ ®x ln æç ÷2 x + 1 ö ÷÷öø /1 è x - 2 øﻟﺩﻴﻨﺎ lim 2 x +1 = 2 : ﻭ ﻤﻨﻪ lim f ( x ) = ln( 2 ) x ® -¥ x ® -¥ x - 2 lim çæ x ® ln æç x + 3 ö÷ ÷ö /2 è(- 3 )- è x + 1 øø ﻟﺩﻴﻨﺎ lim x + 3 = 0 x ® (-3)- x + 1 ﻭ ﻤﻨﻪ ) lim f ( x ) = -¥ﻷﻥ ( lim ln = -¥ 0 + x ® (-3 )- lim çæ x ® ln çæ x + 3 ö÷ ö÷ /3 è(-1 ) + è x + 1 øøﻭ ﻤﻨﻪ ) lim f ( x ) = +¥ﻷﻥ ( lim ln = +¥ lim x + 3 ﻟﺩﻴﻨﺎ :+ ¥ x ® (-1 )+ x ®( -1)+ x + 1 ( ) lim x ® ln( 3 x 3 + x 2 + 1) /4 + ¥ ﻟﺩﻴﻨﺎ ( )lim 3 x 3 + x 2 +1 = +¥ : x® +¥
( lim ln = +¥ )ﻷﻥlim f ( x ) = +¥ ﻭ ﻤﻨﻪ + ¥ x ® +¥ lim (x ® x 3 + x ln (- x ))/ 5 - ¥ x 3 ® -¥ x ® -¥: ﻴﻜﻭﻥ ﻟﻤﺎ: ﻟﺩﻴﻨﺎ x ® -¥( lim ln = +¥ ln( - x ) ® +¥ )ﺍﻋﺘﻤﺩﻥ ﺃﻴﻀﺎ ﻋﻠﻰ ﺍﻟﻤﺒﺭﻫﻨﺔlim f ( x ) = -¥ : ﻭ ﻤﻨﻪ + ¥ x ® -¥ lim (x ® x + ln (x - 5 )) /6 5+ x - 5 ® 0 ﻨﺠﺩ x ® 5 + ﻟﻤﺎ: ﻟﺩﻴﻨﺎ ( lim ln = -¥ )ﻷﻥlim f ( x ) = -¥ ﻭ ﻤﻨﻪ 0 + x ®5 + ( ) lim x ® x 2 + ( 4 x + 2 ) 3 . ln( 2 x +1) /7 æç 1 ö÷ + - è 2 ø( ) lim f ( x ) = lim x ® x 2 + ( 4 x + 2 ) 3 . ln( 2 x +1) :ﻟﺩﻴﻨﺎx ®æç -1 ÷ö+ x ®çæ -1 ÷ö+ è 2 ø è 2 ølim y ln y = 0 ﻷﻥ = 1 4 y ® 0+ æ (ln 5( x x + +83) ) 5 ÷ø÷ö y = 2 x + 1 ﺃﻥ ﻋﻠﻤﺎ li+m ¥ ççè x ® /8 ln y lim f ( x) = æ x + 3 . ln(x x + +33 ) ÷÷öø :ﻟﺩﻴﻨﺎlim = 0 ﻷﻥ xl ®im+¥èçç (5 x + 8) 5 y y ® +¥ x® + ¥ y = x + 3 ﺃﻥ ﻋﻠﻤﺎ =0 lim æç x ® ln( x 2 +1) ÷ö /9 è- ¥ x + 1 ø ]¥ ;0[ ﻋﻨﺼﺭﺍ ﻤﻥ x ﻟﻴﻜﻥ
f ( x ) = ln( x 2 +1) : ﻟﺩﻴﻨﺎ x + 1 ln( x 2 (1 + 1 ) = x 2 x + 1 ln( x 2 ) + ln(1 + 1 ) = x 2 x + 1 2 ln( -x ) + ln(1 + 1 ) = x 2 x + 1 = 2 ln( - x ) + ln çæ1 + 1 ÷ö è x 2 ø x +1 x +1 ln çæ1 + 1 ö è ÷ f ( x ) = 2 . - x . ln( -x ) + x 2 ø : ﺃﻱ ﺃﻥ x +1 - x x + 1 - x ® - 1 x ® -¥: ﻟﻤﺎﻴﻜﻭﻥ: ﻭ ﻟﺩﻴﻨﺎx + 1 ln( - x ) ® 0 - x ln çæ 1 + 1 ö è ÷ x 2 ø ® 0 x + 1 . lim f ( x ) = 0 : ﻭ ﻤﻨﻪ x ® -¥ æ ln( 3 x 2 + 2 x + 1) ö li+m ¥ ççè x ® ln( 2 x 2 + x + 4 ) ÷÷ø /10
:] ﻋﻨﺩﺌﺫ0 ;+¥[ ﻋﻨﺼﺭﺍ ﻤﻥ x ﻟﻴﻜﻥ ln ççæè x 2 çæ 3 + 2 + 1 ÷ö ÷÷øö è x x 2 øf ( x ) = ln çæç x 2 æç 1 + 4 ö÷ ö÷÷ è è 2 + x x 2 ø ø 2 ln( x) + ln çæ 3 + 2 + 1 ÷ö= è x x 2 ø 2 ln( x ) + ln æç 2 + 1 + 4 ÷ö è x x 2 ø é ln çæ 3 + 2 + 1 öù ê è x ÷ ú ln( x ).ê 2 + x 2 ø ú ê ln( x ) ú= êë úû é ln æç 2 + 2 + 4 öù ê è x ÷ ú ln( x ).ê 2 + x 2 ø ú ê ln( x ) ú ëê úû ln æç 3 + 1 + 1 ö è x ÷ 2 + x 2 ø = ln( x ) 4 ln æç 2 + 1 + x 2 ÷ö 2 + è x ø ln( x ) lim f ( x ) = 2 = 1 ﻭ ﻤﻨﻪ x ® +¥ 2 lim çæ x ® ln( x + 2 ) - ln 2 ö÷ /11 0 è x ø : ﻋﻨﺩﺌﺫg(x)=ln(x+2) : ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭg ﻟﺘﻜﻥ
lim f (x) = lim g(x) - g(0) x®0 x ®0 x g(x + 0) - g(0) = lim x®0 x = g¢(0) çæg ¢( x) = 1 ÷ö è x + 2 ø = 1 2 12. ﻨﻔﺱ ﺍﻟﻔﻜﺭﺓ ﺍﻟﻤﺴﺘﻌﻤﻠﺔ ﻓﻲ ﺍﻟﻨﻬﺎﻴﺔ /12 lim æç x ® ln( x - 2 ) ÷ö /13 3 è x - 3 ø lim f ( x ) = lim ln( x - 2 ) - ln(1 ) : ﻟﺩﻴﻨﺎ x ® 3 x ®3 x - 3 g(x)=ln(x2) : ﺒﻭﻀﻊ lim f ( x ) = lim g ( x ) - g ( 3) x® 3 x ®3 x - 3 = g¢(3 ) çæg ¢( x) = 1 ö÷ è x - 3 ø = 1 13. ﻨﻔﺱ ﺍﻟﻔﻜﺭﺓ ﺍﻟﻤﺘﺒﻌﺔ ﻓﻲ ﺍﻟﻨﻬﺎﻴﺔ/ 14 lim æç x ® 1 + ln( x + 1) ÷ö /15 è-1 + x + 1 ølim f ( x ) = lim çæ 1 (1 + ( x + 1) ln( x + 1) )ö÷ : ﻟﺩﻴﻨﺎx® (-1) + èx ®(-1) + x + 1 ø = +¥ ( lim (x ® ( x + 1) ln( x -1) ) = 0 ) ﻷﻥ x ®( -1)+
( ) lim x ® ( x 2 + 7) - ln( x 2 + x + 3) /16 + ¥lim =f ( x ) lim ( x 2 + x + 3) ççèæ x 2 + 7 - ÷÷ln(x x 2 2+ +xx + +33 ) øö ﻟﺩﻴﻨﺎ : x 2 + x + 3 x ® +¥ x ®+¥ ( lim (ln x 2 + x + 3 ) x ® +¥ ) ﻷﻥ x 2 + x + 3 = 0 ﺍﻟﺘﻤﺭﻴﻥ :15 ﻤﺘﺘﺎﻟﻴﺔ ﻋﺩﺩﻴﺔ ﺠﻤﻴﻊ ﺤﺩﻭﺩﻫﺎ ﻤﻭﺠﺒﺔ ﺘﻤﺎﻤﺎ ﺒﺤﻴﺙ(U ) : n nÎ N U0=3 ﻭ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ n ﻓﻲ . ln(Un+1)=2+ln(Un): N / 1 ﺇﻋﻁﺎﺀ ﻋﺒﺎﺭﺓ Un+1 ﺒ ﺩﻻﻟﺔ :Un ﻟﻴﻜ ﻥ nﻋﻨﺼﺭﺍ ﻤﻥ. N ﻟﺩﻴﻨﺎln(Un+1)=2+ln(Un) : ﺃﻱ ﺃﻥ=2 ln(Un+1)ln(Un) : ln çæèç U n +1 ö÷÷ø = -2 ﺃﻥ : ﺃﻱ U n ﺃﻱ ﺃﻥU n +1 = e -2 : U n ﻭ ﻫﺫﺍ ﻴﻌﻨ ﻲ. Un+1=e 2 Un : ﻁﺒﻴﻌﺔ ﺍﻟﻤﺘﺘﺎﻟﻴﺔ:(Un) ﻟﺘﻜﻥ n ﻋﻨﺼﺭﺍ ﻤﻥ.N ﻤﻥ ﺍﻟﺴﺅﺍل ﺍﻟﺴﺎﺒﻕ ﻟﺩﻴﻨﺎUn+1=e 2 Un : ﻭ ﻤﻨﻪ ﺍﻟﻤﺘﺘﺎﻟ ﻴﺔ (Un) ﻫﻨﺩﺴﻴﺔ ﺃﺴﺎﺴﺎﻫﺎ r ﺤﻴﺙ . r=e 2 / 2 ﺇﻋﻁﺎﺀ ﻋﺒﺎﺭﺓ ﺍﻟﺤﺩ ﺍﻟﻌﺎﻡ ﻟﻠﻤﺘﺘﺎﻟﻴﺔ:(Un) ﻟﻴﻜﻥ n ﻋﻨﺼﺭﺍ ﻤﻥ.N ﻟﺩﻴﻨﺎUn=U0.r n : =3.(e 2) n =3.e 2n ﺩﺭﺍﺴﺔ ﺍﺘﺠﺎﻩ ﺘﻐﻴﺭ ﺍﻟﻤﺘﺘﺎﻟﻴﺔ:(Un)
ﻟﻴﻜﻥ n ﻋﻨﺼﺭﺍ ﻤﻥ.N ﻟﺩﻴﻨﺎUn+1Un=3.e 2(n+1) 3.e 2n : =3.e 2n2 (1e2 ) ﻭ ﺒﻤﺎ ﺃﻥ (1e2 < 0) ﻭ(3.e 2n2 >0) ﻓﺈﻥUn+1Un <0: ﻭ ﻤﻨﻪ ﺍﻟﻤﺘﺘﺎﻟﻴﺔ (Un) ﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ. ﺩﺭﺍﺴﺔ ﺘﻘﺎﺭﺏ ﺍﻟﻤﺘﺘﺎﻟﻴﺔ : (Un) (Un) ﻫﻨﺩﺴﻴﺔ ﺃﺴﺎﺴﻬﺎ r ﺤﻴﺙ r=e 2 ﺒﻤﺎ ﺃﻥ (Un) : ﻫﻨﺩﺴﻴﻭ ﻭ ﺃﺴﺎﺴﻬﺎ ﻴﺤﻘﻕ1<r<1 ﻓﺈﻥ (Un) : ﻤﺘﻘﺎﺭﺒﺔ ﻨﺤﻭ0.: /3 ﻁﺒﻴﻌﺔ ﺍﻟﻤﺘﺘﺎﻟﻴﺔ :(Vn) ﻟﻴﻜﻥ n ﻋﻨﺼﺭﺍ ﻤﻥ.N ﻟﺩﻴﻨﺎ Vn=ln(Un) : =ln(3.e 2n) =ln3.ln(e 2n ) =ln32n ﻋﻨﺩﺌﺫVn+1Vn=(ln32n2)(ln32n) : ﻭ ﻤﻨﻪ ﺍﻟﻤﺘﺘﺎﻟﻴﺔ (Vn) ﻫﻨﺩﺴﻴﺔ ﺃﺴﺎﺴﻬﺎ r¢ﺤﻴﺙr¢=2 : ﺤﺴﺎﺏ ﺍﻟﻤﺠﻤﻭﻉ Sn ﺒﺩﻻﻟﺔ ﺍﻟﻌﺩﺩ ﺍﻟﻁﺒﻴﻌﻲ :n ﻟﻴﻜﻥ n ﻋﻨﺼﺭﺍ ﻤﻥ.N ﻟﺩﻴﻨﺎS=V0+V1+…..+Vn : = n +1 (V0 + V n ) 2 n + 1 2 =( ) ln(U 0 ) + ln 3 - 2 n = ( n + (1) ln 3 - n ) ﺤﺩﻭﺩ ﺍﻟﻤﺘﺘﺎﻟﻴﺔ(Un) ﺍﺴﺘﻨﺘﺎﺝ ﻋﺒﺎﺭﺓ ﺍﻟﺠﺩﺍﺀ Pn ﺒﺩﻻﻟﺔ ﺍﻟﻌﺩﺩ ﺍﻟﻁﺒﻴﻌﻲ :n ﻟﻴﻜﻥ n ﻋﻨﺼﺭﺍ ﻤﻥ.N ﻜﻠﻬﺎ ﻤﻭﺠﺒﺔ ﻟﺩﻴﻨﺎ Pn=u0´u1´……´un : ﻋﻨﺩﺌﺫln(Pn)=ln(u0´u1´……´un) :
=ln(u0)+ln(u1)+……+ln(un) =v0+v1+……+vn =Sn ﻭ ﻋﻠﻴ ﻪ ln(Pn)=Sn: ﻭ ﺒﺎﻟﺘﺎﻟﻲ Pn=eS n : =e( n+1)(ln(3)n) ﺍﻟﺘﻤﺭﻴﻥ :16 (f x ) = 9 ln( x ) ﺒﺎﻟﺩﺴﺘﻭﺭ ﺍﻟﻤﻌﺭﻓﺔ ﺍﻟﺩﺍﻟﺔ f : x /1 ﺩﺭﺍﺴﺔ ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ :f ﻨﺠﺩ ﺠﺩﻭل ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ fﻤﻤﺜﻼ ﻓﻲ ﺍﻟﺘﺎﻟ ﻲ: x ¥ 0 e +¥ f ¢(x) f(x) + 9 e ¥ 0 f ¢( x ) =9. 1 - ln( x ) x 2 /2 ﺩﺭﺍﺴﺔ ﺍﻟﻔﺭﻭﻉ ﺍﻟﻼﻨﻬﺎﺌﻴﺔ ﻟﻠﻤﻨﺤﻨﻲ (Cf) ﺍﻟﻤﻤﺜل ﻟﻠﺩﺍﻟﺔ : f ﻭ ﻤﻨﻪ ﺍﻟﻤﺴﺘﻘﻴﻡ ﺍﻟﺫﻱ x=0 ﻤﻌﺎﺩﻟﺔ ﻟﻪ ﻫﻭ ﻤﺴﺘﻘﻴﻡ ﻤﻘﺎﺭﺏ ﻟﻠﻤﻨﺤﻨﻲlim f = -¥.(Cf) ﻟﺩﻴﻨﺎ 0+ ﻭ ﻤﻨﻪ ﺍﻟﻤﺴﺘﻘﻴﻡ ﺍﻟﺫﻱ y=0 ﻤﻌﺎﺩﻟﺔ ﻟﻪ ﻫﻭ ﻤﺴﺘﻘﻴﻡ ﻤﻘﺎﺭﺏ ﻟﻠﻤﻨﺤﻨﻲlim f = -¥ ﻭ ﻟﺩﻴﻨﺎ : + ¥ . (Cf) /3 ﻤﻌﺎﺩﻟﺔ ﺍﻟﻤﺴﺘﻘﻴﻡ ، (d) ﺍﻟﻤﻤﺎﺱ ﻟﻠﻤﻨﺤﻨ ﻲ) (Cfﻓﻲ ﻨﻘﻁﺔ ﺘﻘﺎﻁﻌﻪ ﻤﻊ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﻔﻭﺍﺼل: ﻨﻘﻁﺔ ﺘﻘﺎﻁﻊ (Cf) ﻤﻊ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﻔﻭﺍﺼل ﻫﻲ A ﺤﻴﺙA(1 ;0) ﻋﻨﺩﺌﺫ :ﻤﻌﺎﺩﻟﺔ ﻟـ (d) ﻤﻌﺭﻓﺔ ﺒ ـ: y=f ¢(1).(x1)+f(1) =9(x1)+0 =9x9
ﻭ ﻤﻨﻪ y)9x9 ﻫﻲ ﻤﻌﺎﺩﻟﺔ ﻟﻠﻤﻨﺤﻨﻲ (Cf) ﻓﻲ ﺍﻟﻨﻘﻁﺔ. A /4 ﺭﺴﻡ ﺍﻟﻤﺴﺘﻘﻴﻡ (d) ﻭ ﺍﻟﻤﻨﺤﻨﻲ:( Cf) y 6 )5 (d4 ® ® ( Cf ) 3 2 1 ®j1 0 ®i 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 x 1 2 3 4 5 6 /ﺤﺴﺎﺏ ﺍﻟﻤﺴﺎﺤﺔ ﺍﻟﻤﻘﺩﺭﺓ ﺒﺎﻟﺴﻨﺘﻴﻤﺘﺭﺍﻟﻤﺭﺒﻊ ﻟﻠﺤﻴﺯ ﺍﻟﻤﺤﺘﻭﻱ5 ﺍﻟﻤﺤﺩﺩ ﺒﺎﻟﻤﻨﺤﻨﻲ (Cf) ﻭ ﺍﻟﻤﺴﺘﻘﻴﻤﺎﺕ ﺫﺍﺕ ﺍﻟﻤﻌﺎﺩﻻﺕ (D) x=e2 ، x=e ،y =0 ﻟﺘﻜﻥ Aﺍﻟﻤﺴﺎﺤﺔ ﺍﻟﻤﻌﺘﺒﺭﺓ ﻋﻨﺩﺌﺫ: A e 2 9. ln( x ) dx x = ò e e 2 1 (ln( x ))1 d x x = 9 ò e = 9 ëéê (ln ( x)) 2 ù e 2 2 úû e = 9çæ 2 2 - 12 ÷ö è 2 2 ø = 27 2 ﻭ ﺒﺎﻟﺴﻨﺘﻴﻤﺘﺭ ﺍﻟﻤﺭﺒﻊ :ﺃﻱ 27 ´1 ´1c m2 ﺃﻱ 27 cm2 2 2
ﺍﻟﺘﻤﺭﻴﻥ :17 f ( x ) = ln çæ x ö ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ÷ f: è x + 1 ø /1 ﺩﺭﺍﺴﺔ ﺘﻐﻴﺭﺍﺕ ﻟﺩﺍﻟﺔ :fﺒﺈﺘﺒﺎﻉ ﻨﻔﺱ ﺍﻟﻤﺭﺍﺤل ﺍﻟﻤﻌﺘﺎﺩﺓ ﻨﺠﺩ ﺃﻥ ﺠﺩﻭل ﺘﻐﻴﺭﺍﺕ ﻴﺘﻤﺜل ﻓﻲ ﺍﻟﺘﺎﻟﻲ f:x ¥ 1 0 +¥ f ¢(x) + + f (x) +¥ 0 0 ¥ /2 ﺘﻌﻴﻴﻥ ﺍﻟﻤﻤﺎﺴﺎﺕ ﻟ ـ) (Cfﺍﻟﻤﻭﺍﺯﻴﺔ ﻟﻠﻤﺴﺘﻘﻴﻡ (D) ﺫﻭ ﺍﻟﻤﻌﺎﺩﻟﺔy = 1 x + 3 : 2 ﻟﻴﻜﻥ x ﻋﻨﺼﺭﺍ ﻤﻥ ] - ¥; -1[ È]0 ; + ¥[ X ﺤل ﻟﻤﺴﺄﻟﺘﻨﺎ ﻴﻌﻨﻲ ﺃﻥf ¢( x ) = 1 : 2 ﻭ ﻫﺫﺍ ﻴﻌﻨ ﻲx 2 +x2=0 : ﻭ ﻫﺫﺍ ﻴﻌﻨﻲ (x=2) : ﺃﻭ. (x=1) ﻭ ﻤﻨﻪ ﻫﻨﺎﻙ ﻨﻘﻁﺘﺎﻥ ﻤ ﻥ) (Cfﻨﺴﻤﻴﻬﺎ A1 ﻭ A2 ﺤﻴﺙ ﺍﻟﻤﻤﺎﺱ ﻟ ـ) (Cfﻓﻲ ﻜل ﻤﻨﻬﻤﺎ ﻴﻭﺍﺯ ﻱ) (Dﺃﻴﻥ A1(1 ;ln(2)) ﻭ. A2(2 ;ln(2) ﻟﻴﻜﻥ ( D1) ﺍﻟﻤﻤﺎﺱ ﻟـ( Cf) ﻋﻨﺩ A1 ﻭ ﻟﻴﻜﻥ(D2) ﻋﻨﺩﺌﺫ: ( D 1) : y = f ¢(1 ) ( x -1) + f (1 ) ( D2 ) : y = f ¢( -2 ).( x + 2 ) + f ( -2 ) ﺃﻱ ﺃﻥ : ( D1 ) : y = 1 (x - 1 ) + ln( 2 ) 2 2 1 .( x + =( D2 ) : y 2 2 ) + ln( 2)
ﺃﻱ ﺃﻥ: =( D1 ) : y 1 x - 1 - ln( 2) 2 4 =( D 2 ) : y 1 . x + 1 + ln( 2) 2 w 1 ﻫﻲ ﻤﺭﻜﺯ ﺘﻨﺎﻅﺭ ﻟﻠﻤﻨﺤﻨﻲ (- ;0 ) .(Cf) /3 ﺇﺜﺒﺎﺕ ﺃﻥ ﺍﻟﻨﻘﻁﺔ wﺤﻴﺙ 2 ﻤﻬﻤﺎ ﻴﻜﻭﻥ x ﻴﻨﺘﻤﻲ ﺇﻟﻰ]¥ ;1[È]0 ;+¥[ ﻴﻨﺘﻤﻲ ﺇﻟﻰ ﻫﺫﻩ ﺍﻟﻤﺠﻤﻭﻋﺔ2æç - 1 ö÷ - x. ﻟﺩﻴﻨﺎ : è 2 ø ﻷﻥxÎ]¥;1[È]0;+¥[ : ﻴﻌﻨﻲ ﺃﻥ ( x<1) : ﺃﻭ ( x>0) ﺃﻱ ﺃﻥ ( x>1) : ﺃﻭ(–x<0) ﻭ ﻫﺫﺍ ﻴﻌﻨﻲ ﺃﻥ (1x>0) : ﺃﻭ(1x<1) ﻭ ﻫﺫﺍ ﻴﻌﻨﻲ ﺃﻥ æç 2æç - 1 ÷ö - x > 0 ÷ö :ﺃﻭ çæ 2çæ - 1 ö÷ - x < -1÷ö è è 2 ø ø è è 2 ø ø ﻟﺩﻴﻨﺎ :ﻤﻥ ﺃﺠل x ﻴﻨﺘﻤﻲ ﺇﻟﻰ ﺍﻟﻤﺠﻤﻭﻋﺔ]¥ ;1[È]0 ;+¥[ f æç 2æç - 21 ö÷ø - x ÷ö + =f ( x ) f ( -1 - x ) + f ( x ) èè ø ÷= ln çæ -1 - x ÷ö + ln çæ x ö è - x ø è x +1 ø = ln çæ x +1 . x ÷ö è x x +1 ø = ln(1) = 0 = 2( 0)
ﻭ ﻤﻨﻪ ﻭ ﺤﺴﺏ ﺍﻟﻤﺒﺭﻫﻨﺔ ﻨﺠﺩ ﺃﻥ ﺍﻟﻨﻘﻁﺔ wﻫﻲ ﻤﺭﻜﺯ ﺘﻨﺎﻅﺭ ﻟﻠﻤﻨﺤﻨﻲ.(C f) /4 ﺩﺭﺍﺴﺔ ﺍﻟﻔﺭﻭﻉ ﺍﻟﻼﻨﻬﺎﺌﻴﺔ ﻟﻠﻤﻨﺤﻨﻲ .(Cf) ﻭ ﻤﻨﻪ ﺍﻟﻤﺴﺘﻘﻴﻡ ﺍﻟﺫﻱ y=0 ﻤﻌﺎﺩﻟﺔ ﻟﻪ ﻫﻭ ﻤﺴﺘﻘﻴﻡ ﻤﻘﺎﺭﺏlim f = 0 lim f = 0 ﻟﺩﻴﻨﺎ : ﻭ - ¥ + ¥ ﻟﻠﻤﻨﺤﻨﻲ ﻟ ـ).(Cf ﻭ ﻤﻨﻪ ﺍﻟﻤﺴﺘﻘﻴﻡ ﺍﻟﺫﻱ x=1 ﻤﻌﺎﺩﻟﺔ ﻟﻪ ﻫﻭ ﻤﺴﺘﻘﻴﻡ ﻤﻘﺎﺭﺏ ﻟﻠﻤﻨﺤﻨﻲ ﻟـlim f = +¥ ﻭ ﻟﺩﻴﻨﺎ : ( -1 ) - .(Cf) ﻭ ﻤﻨﻪ ﺍﻟﻤﺴﺘﻘﻴﻡ ﺍﻟﺫﻱ x=0 ﻤﻌﺎﺩﻟﺔ ﻟﻪ ﻫﻭ ﻤﺴﺘﻘﻴﻡ ﻤﻘﺎﺭﺏ ﻟﻠﻤﻨﺤﻨﻲ ﻟـlim f = -¥ ﻭ ﻟﺩﻴﻨﺎ : 0 + .(Cf) * ﺭﺴﻡ ﺍﻟﻤﻨﺤﻨﻲ .(C f) y 6 5 4 3 2 1 ®j9 8 7 6 5 4 3 2 1 0 i® 1 2 3 4 5 6 7 8 x 1 ( Cf ) 2 3 4 5 6 / 5 ﺇﺜﺒﺎﺕ ﺃﻥ F ﻫﻲ ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ fﻋﻠﻰ ﺍﻟﻤﺠﺎل]0 ;+¥[ ﺍﻟﺩﺍﻟﺔ F ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﺍﻟﻤﺠﺎل.]0 ;+¥[ ﻟ ﻴﻜﻥ x ﻋﻨﺼﺭﺍ ﻤﻥ ﺍﻟﻤﺠﺎل]0 ;+¥[ ﻟﺩﻴﻨﺎF ¢( x ) = 1. ln( x ) + x. 1 -1. ln( x +1) - ( x +1) . 1 : x x +1 = ln( x ) +1 - ln( x +1) -1 = ln( x ) - ln( x +1)
÷= ln æç x ö è x +1 ø= f (x ) ﻭ ﻤﻨﻪ F ﻫﻲ ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ fﻋﻠﻰ ﺍﻟﻤﺠﺎل]0 ;+¥[ g/ 6 ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ g ( x ) = ln çæ x + 1 ö÷ : è x ø ﺇﻨﺸﺎﺀ ﺍﻟﻤﻨﺤﻨﻲ (Cg) ﻤﺜل ﻟﻠﺩﺍﻟﺔ g ﺒﺎﻟﻨﺴﺒﺔ ﺇﻟﻰ ﻨﻔﺱ ﺍﻟﻤﻌﻠﻡ ﺍﻟﺴﺎﺒﻕ: ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ g ﻫﻲ]¥ ;1[È]0 ;+¥[ ﻟﻴﻜﻥ x ﻋﻨﺼﺭﺍ ﻤﻥ]¥ ;1[È]0 ;+¥[ ﻟﺩﻴﻨﺎg (x ) = ln x + 1 : x = - ln x x + 1 = - f (x ) ﻭ ﻤﻨﻪ (Cg) ﻴﻨﺎﻅ ﺭ) (Cfﺒﺎﻟﻨﺴﺒﺔ ﻟﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﻔﻭﺍﺼل. y 6 5 4 3 2 1 ®j ( Cg ) 9 8 7 6 5 4 3 2 1 0 ®i 1 2 3 4 5 6 7 8 x 1 ( Cf ) 2 3 4 5 6 ﺏ( ﺤﺴﺎﺏ ﺍﻟﻤﺴﺎﺤﺔ ،ﺍﻟﻤﻘﺩﺭﺓ ﺒﺎﻟﺴﻨﺘﻴﻤﺘﺭ ﺍﻟﻤﺭﺒﻊ ،ﻟﻠﺤﻴﺯ ﺍﻟﻤﺴﺘﻭﻱ (D) ﺍﻟﻤﺤﺩﺩ ﺒﺎﻟﻤﻨﺤﻨﻴﻴﻥ (Cf) ﻭ(Cg) ﻭ ﺍﻟﻤﺴﺘﻘﻴﻤﻴﻥ ﺫﺍ ﺍﻟﻤﻌﺎﺩﻟﺘﻴﻥ x=1 ﻭx=2 ﻓﻲ ﺍﻟﻤﺠﺎل [1 ;2] ﻟﺩﻴﻨﺎg(x)>f(x) :
ﻭ ﻜل ﻤﻥ f ﻭ g ﻋﻠﻰ ﺍﻟﻤﺠﺎ ل] [1 ;2ﻤﺴﺘﻤﺭﺓ : ﻨﺴﻤﻲ ﺍﻟﻤﺴﺎﺤﺔ ﺍﻟﻤﻌﺘﺒﺭﺓ ﻋﻨﺩﺌﺫA: 2 A = ò (g(x) f (x))dx 1 = 2 æ ln çæ x + 1 ÷ö - ln æç ÷x ö ö÷ dx ç è x ø è x + 1 ø ø ò è1 2 = -2 ò f ( x ) dx 1 = -2[ x ln x - ( x +1) ln( x +1) ]1 2 = -2( 2 ln( 2) - 3 ln( 3) - 0 + 2 ln( 2) ) = 6 ln( 3) - 8 ln( 2) ﻭ ﺒﺎﻟﺴﻨﺘﻴﻤﺘﺭ ﻤﺭﺒﻊ ﺍﻟﻤﺴﺎﺤﺔ ﻫﻲ : ( 6 ln( 3) - 8 ln( 2 )) ´ 2 ´ 2 cm2 ﺃﻱ ﻫﻲ24 ln( 3) - 32 ln( 2 ) :
ﺍﻟﺩﻭﺍل ﺍﻷﺴﻴﺔ ﺫﺍﺕ ﺍﻷﺴﺎﺱ ﻫـ ﺍﻟﻜﻔﺎﺀﺍﺕ ﺍﻟﻤﺴﺘﻬﺩﻓﺔ: -ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻭﻤﻌﺭﻓﺔ ﺍﻟﺨﻭﺍﺹ ﺍﻟﻤﻤﻴﺯﺓ ﻟﻬﺎ. -ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻭﻤﻌﺭﻓﺔ ﺍﻟﺨﻭﺍﺹ ﺍﻟﻤﻤﻴﺯﺓ ﻟﻬﺎ. -ﺍﺴﺘﻌﻤﺎل ﺤﺎﺴﺒﺔ ﻟﺤﺴﺎﺏ ﻗﻴﻡ ﺩﻭﺍل ﺘﺩﺨل ﻓﻲ ﺘﻌﺭﻴﻔﻬﺎ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ. -ﺤل ﻤﻌﺎﺩﻻﺕ ﻭﻤﺘﺭﺍﺠﺤﺎﺕ ﺘﺘﻀﻤﻥ ﻟﻭﻏﺎﺭﻴﺘﻤﺎﺕ. -ﺤﺴﺎﺏ ﻨﻬﺎﻴﺎﺕ ﺠﺩﺍﺀﺍﺕ ﺃﻭ ﺤﻭﺍﺼل ﻗﺴﻤﺔ ﺘﺩﺨل ﻓﻴﻬﺎ exp(x)،lnx، xn : -ﺩﺭﺍﺴﺔ ﺩﻭﺍل ﻤﻥ ﺍﻟﺸﻜل expo u -ﺩﺭﺍﺴﺔ ﺩﻭﺍل ﻤﻥ ﺍﻟﺸﻜل expo u -ﺍﺴﺘﻌﻤﺎل ﺍﻟﻜﺘﺎﺒﺔ ﺍﻟﻤﺄﻟﻭﻓﺔ exlim x.ex = 0 ﻭ lim ex ∞= + -ﻤﻌﺭﻓﺔ ﻭ ﺘﻔﺴﻴﺭ ﺍﻟﻨﻬﺎﻴﺘﻴﻥ x∞x→− ∞x→+lim x.ex = 0 ﻭ lim ex ∞= + -ﻤﻌﺭﻓﺔ ﻭ ﺘﻔﺴﻴﺭ ﺍﻟﻨﻬﺎﻴﺘﻴﻥ x∞x→− ∞x→+ -ﺤل ﻤﺸﻜﻼﺕ ﻤﺘﻌﻠﻘﺔ ﺒﺘﺴﺩﻴﺩ ﺃﻭ ﺇﻴﺩﺍﻉ ﺘﺩﺨل ﻓﻴﻬﺎ ﺍﻟﻠﻭﻏﺎﺭﻴﺘﻤﺎﺕ ﻭ ﺍﻷﺴﻴﺎﺕ
ﺘﺼﻤﻴﻡ ﺍﻟﺩﺭﺱ -ﻨﺸﺎﻁ ﺘﻤﻬﻴﺩﻱ - 1ﺘﻌﺭﻴﻑ ،ﺘﺭﻤﻴﺯ ،ﺍﺼﻁﻼﺡ - 2ﺨﻭﺍﺹ ﺃﻭﻟﻴﺔ ﺍﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ - 3ﺨﻭﺍﺹ ﺠﺒﺭﻴﺔ ﺍﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ - 4ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﺍﻷﺴﻴﺔ. - 5ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﺩﺍﻟﺔ ﻤﻥ ﺍﻟﺸﻜل )xleu(x - 6ﻨﻬﺎﻴﺎﺕ ﻗﺎﻋﺩﻴﺔ - 7ﺠﺩﻭل ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻭ ﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ - 8ﺍﻟﺘﺯﺍﻴﺩ ﺍﻟﻤﻘﺎﺭﻥ ﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻭ ﺍﻟﺩﻭﺍل ﻗﻭﻯ - 9ﺍﻟﻘﻭﻯ ﺫﺍﺕ ﺍﻷﺱ ﺍﻟﺤﻘﻴﻘﻲ ﻭ ﺍﻷﺴﺎﺱ ﺍﻟﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ - 10ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﺫﺍﺕ ﺍﻷﺴﺎﺱ a – 11ﺘﻤﺎﺭﻴﻥ ﻭﻤﺸﻜﻼﺕ ﺤﻭل ﺍﻟﺩﻭﺍل ﺍﻷﺴﻴﺔ ﻭﺍﻟﺩﻭﺍل ﺍﻟﻠﻭﻏﺎﺭﻴﺘﻤﻴﺔ. – 12ﺤﻠﻭل ﺍﻟﺘﻤﺎﺭﻴﻥ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻭﺍﻟﺩﻭﺍل ﺍﻟﻠﻭﻏﺎﺭﻴﺘﻤﻴﺔ.
ﻨﺸﺎﻁ ﺘﻤﻬﻴﺩﻱ ﻫﺩﻑ ﺍﻟﻨﺸﺎﻁ :ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ * ﺍﻷﺴﺌﻠﺔ: -1-ﺃﺜﺒﺕ ﺃﻨﻪ ﻴﻭﺠﺩ ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ ﻭﺤﻴﺩ ﺼﻭﺭﺘﻪ lnﺘﺴﺎﻭﻱ .2 -2-ﺃ( ﻨﻀﻊ [∞، ]0 ;+ﻋﻴﻥ ) ln(Iﺼﻭﺭﺓ ﺍﻟﻤﺠﺎل Iﺒﺎﻟﺩﺍﻟﺔ . lnﺏ( ﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ ﻜﻴﻔﻴﺎ،ﺃﺜﺒﺕ ﺃﻨﻪ ﻴﻭﺠﺩ ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ ﻭﺤﻴﺩ bﺼﻭﺭﺘﻪ ﺒﺎﻟﺩﺍﻟﺔ ln ﺘﺴﺎﻭﻱ aﺜﻡ -ﺒﺎﺴﺘﻌﻤﺎل ﺍﻟﻤﻨﺤﻨﻲ ﺍﻟﻤﻤﺜل ﻟﻠﺩﺍﻟﺔ lnﻓﻲ ﺍﻟﻤﺴﺘﻭﻱ ﺍﻟﻤﻨﺴﻭﺏ ﺇﻟﻰ ﻤﻌﻠﻡ ) (O; i; jﺃﻨﺸﺊ ﺍﻟﻨﻘﻁﺔ ) B(b ;0ﺍﻨﻁﻼﻗﺎ ﻤﻥ ﺍﻟﻨﻘﻁﺔ ). A(0 ;a -ﻋﻴﻥ bﻓﻲ ﺍﻟﺤﺎﻟﺔ a=nﺤﻴﺙ nﻋﺩﺩ ﺼﺤﻴﺢ. * ﺍﻷﺠﻭﺒﺔ:-1-ﺇﻴﺠﺎﺩ ﻤﺠﻤﻭﻋﺔ ﺍﻷﻋﺩﺍﺩ ﺍﻟﺤﻘﻴﻘﻴﺔ ﺍﻟﻤﻭﺠﺒﺔ ﺘﻤﺎﻤﺎ ﺍﻟﺘﻲ ﺼﻭﺭﺘﻬﺎ ﺒﺎﻟﺩﺍﻟﺔ lnﺘﺴﺎﻭﻱ 2ﻴﻌﻨﻲ ﺇﻴﺠﺎﺩ ﻤﺠﻤﻭﻋﺔ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ (α)..... ln(x)=2 ﺤﻴﺙ xﻫﻭ ﺍﻟﻤﺠﻬﻭل ﻓﻲ ℜ*+ﻭ ﻤﻥ ﺃﺠل xﻓﻲ ℜ*+ﻟﺩﻴﻨﺎ : ) (αﺘﻜﺎﻓﺊ ln(x)=2.1 ﺘﻜﺎﻓﺊ )ln(x)=2ln(e ﺘﻜﺎﻓﺊ ) ) ln(x)=ln(e2ﻤﻥ ﺨﻭﺍﺹ ﺍﻟﺩﺍﻟﺔ ( ln ﻭ ﻤﻨﻪ (α) :ﺘﻜﺎﻓﺊ ) x=exﻤﻥ ﺨﻭﺍﺹ ﺍﻟﺩﺍﻟﺔ (ln ﻤﻨﻪ ﻤﺠﻤﻭﻋﺔ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ ) (αﻫﻲ }{e2 ﻭ ﻋﻠﻴﻪ :ﻴﻭﺠﺩ ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻤﻭﺠﺏ ﻭﺤﻴﺩ ﺼﻭﺭﺘﻪ ﺒﺎﻟﺩﺍﻟﺔ lnﺘﺴﺎﻭﻱ 2ﻭ ﻫﺫﺍ ﺍﻟﻌﺩﺩ ﻫﻭ . e2 -2-ﺃ([∞I=]0 ;+ ﻟﺩﻴﻨﺎ lnﻤﺴﺘﻤﺭﺓ ﻭ ﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ [∞]0 ;+ﻤﻨﻪ ﻭ ﺤﺴﺏ ﺍﻟﻤﺒﺭﻫﻨﺔ) ﺤﻭل ﺼﻭﺭﺓ ﻤﺠﺎل ﺒﺎﻟﺩﺍﻟﺔ ﻤﺴﺘﻤﺭﺓ ﻭ ﺭﺘﻴﺒﺔ ﺘﻤﺎﻤﺎ(lim ln = lnﻭ ∞− = ∞+ ﻟﺩﻴﻨﺎ: ) ln(Iﻭ [=]lim ln;lim ln 0+ ∞0+ +
ﻭ ﻋﻠﻴﻪ: )[∞ ln(]0;+ﺼﻭﺭﺓ ﺍﻟﻤﺠﺎل [∞ ]0;+ﺒﺎﻟﺩﺍﻟﺔ lnﻫﻲ ﺍﻟﻤﺠﺎل [∞] − ∞;+ ﺏ(ﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ ﻜﻴﻔﻴﺎ ﻟﺩﻴﻨﺎ a :ﻴﻨﺘﻤﻲ ﺇﻟﻰ ﺍﻟﻤﺠﺎل )[∞ln(]0;+ lnﻤﺴﺘﻤﺭﺓ ﻭ ﺭﺘﻴﺒﺔ ﺘﻤﺎﻡ ﻋﻠﻰ ﺍﻟﻤﺠﺎل [∞]0;+ﻤﻨﻪ ﻭ ﺤﺴﺏ ﻤﺒﺭﻫﻨﺔ ﺍﻟﻘﻴﻡ ﺍﻟﻤﺘﻭﺴﻁﺔ ﻓﻲ ﺤﺎﻟﺔ ﺩﺍﻟﺔ ﻤﺴﺘﻤﺭﺓ ﻭ ﺭﺘﻴﺒﺔ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﻤﺠﺎل ،ﺍﻟﻤﻌﺎﺩﻟﺔ ln(x)=a ،ﺤﻴﺙ xﻫﻭ ﺍﻟﻤﺠﻬﻭل ﻟﻬﺎ ،ﻓﻲ ﺍﻟﻤﺠﺎل [∞ ]0;+ﺤل ﻭﺤﻴﺩ،ﻭ ﺇﺫﺍ ﺴﻤﻴﻨﺎ bﻫﺫﺍ ﺍﻟﺤل ،ﻴﻜﻭﻥ: ﻴﻭﺠﺩ ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ ﻭﺤﻴﺩ bﻴﺤﻘﻕ ln(b)=aﺃﻱ ﺼﻭﺭﺘﻪ ﺒﺎﻟﺩﺍﻟﺔ lnﺘﺴﺎﻭﻱ . a ﻟﻴﻜﻥ ) (Gﺍﻟﻤﻨﺤﻨﻲ ﺍﻟﻤﻤﺜل ﻟﻠﺩﺍﻟﺔ lnﻓﻲ ﺍﻟﻤﺴﺘﻭﻱ ﺍﻟﻤﻨﺴﻭﺏ ﺇﻟﻰ ﻤﻌﻠﻡ ) (O; i; jﻟﺩﻴﻨﺎ ln(b)=a ﻤﻨﻪ ﺍﻟﻨﻘﻁﺔ ) C(b ;aﺘﻨﺘﻤﻲ ﺇﻟﻰ ﺍﻟﻤﻨﺤﻨﻲ ) (Gﻤﻨﻪ bﻫﻭ ﻓﺎﺼﻠﺔ ﺍﻟﻨﻘﻁﺔ ﻤﻥ ﺍﻟﻤﻨﺤﻨﻲ)(Gﺍﻟﺘﻲ ﺘﺭﺘﻴﺒﻬﺎ ﻴﺴﺎﻭﻱ aﻤﻨﻪ ﺍﻟﺸﻜل . 3y 2 )A(0;a 1 →j 0 →i 1 2 3 B(b;0) 4 5 6 7 8 x -1 )(G -2 -3-ﻟﺩﻴﻨﺎ bﻤﻌﺭﻑ ﺒﺎﻟﻤﺴﺎﻭﺍﺓ (β).....ln(b)=aﺘﺼﺒﺢ ln(b)=nﺃﻱ ln(b)=n.1ﺃﻱ )ln(b)=n.ln(e ﺃﻱ ). ln(b)=ln(en ﻤﻨﻪ :ﻟﻤﺎ a=nﺤﻴﺙ nﻋﺩﺩ ﺼﺤﻴﺢ b=en ، ﺍﻟﻤﻼﺤﻅﺔ :ﻤﻥ ﺨﻼل ﻫﺫﺍ ﺍﻟﻨﺸﺎﻁ ﻟﻘﺩ ﻋﻴﻨﺎ ﺩﺍﻟﺔ :ﺍﻟﺩﺍﻟﺔ ﺍﻟﺘﻲ ﺘﺭﻓﻕ ﺒﻜل ﻋﺩﺩ ﺤﻘﻴﻕ aﺍﻟﻌﺩﺩ ﺍﻟﺤﻘﻴﻘﻲ ﺍﻟﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ b ﺍﻟﺫﻱ ﻴﺤﻘﻕ . ln(b)=a ﻫﺫﻩ ﺍﻟﺩﺍﻟﺔ ﻫﻲ ﺒﺎﻟﺘﻌﺭﻴﻑ \"ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ\" ﺍﻟﺘﻲ ﺭﻤﺯﻫﺎ . exp
ﻫﻜﺫﺍ :ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ exp(a) ،aﺼﻭﺭﺓ aﺒﺎﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻫﻲ ﺍﻟﻌﺩﺩ ﺍﻟﺤﻘﻴﻘﻲ ﺍﻟﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ ﺍﻟﺫﻱ ﺼﻭﺭﺘﻪ ﺒﺎﻟﺩﺍﻟﺔ lnﺘﺴﺎﻭﻱ . aﺇﺫﻥ :ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ exp(a)>0: aﻭ ]) ln[exp(aﻭ ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺼﺤﻴﺢ : n . exp(n)=en ﺒﻴﺎﻨﻴﺎ: y )(Ga2 )exp(a1 )exp(a2 xa1 1 →j 0 i→ 1 ) (Gﺍﻟﻤﻨﺤﻨﻲ ﺍﻟﻤﻤﺜل ﻟﻠﺩﺍﻟﺔ lnﺒﺎﻟﻨﺴﺒﺔ ﺇﻟﻰ ﺍﻟﻤﻌﻠﻡ ). (O; i; j
ﺘﻌﺭﻴﻑ ،ﺘﺭﻤﻴﺯ ،ﺍﺼﻁﻼﺡ ﻜل ﺩﺍﻟﺔ ﻤﻌﺘﺒﺭﺓ ﻓﻲ ﻫﺫﺍ ﺍﻟﺩﺭﺱ ﻫﻲ ﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ ﻟﻤﺘﻐﻴﺭ ﺤﻘﻴﻘﻲ. ﻭ ﻓﻲ ﺤﺎﻟﺔ ﻋﺩﻡ ﺍﻟﺘﺤﺩﻴﺩ ،ﻜل ﻤﺠﺎل ﻤﻌﺘﺒﺭ ﻫﻭ ﻤﺠﺎل –ﻤﻥ -ℜﻴﺤﺘﻭﻱ ﻤﺠﺎﻻ ﻤﻔﺘﻭﺤﺎ ﻏﻴﺭ ﺨﺎل. -ﺃ-ﺘﻌﺭﻴﻑ ،ﺘﺭﻤﻴﺯ : ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻫﻲ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺭﻤﺯ ﺇﻟﻴﻬﺎ ﺒﺎﻟﺭﻤﺯ expﻭ ﺍﻟﻤﻌﺭﻓﺔ ﺒﻤﺎ ﻴﻠﻲ: * ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ expﻫﻲ .ℜ * ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ ، exp(x)،xﺼﻭﺭﺓ xﺒﺎﻟﺩﺍﻟﺔ ، expﻫﻲ ﺍﻟﻌﺩﺩ ﺍﻟﺤﻘﻴﻘﻲ ﺍﻟﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ y ﺍﻟﻤﻌﺭﻑ ﺒﺎﻟﻤﺴﺎﻭﺍﺓ .ln(y)=x -ﺏ -ﺍﺼﻁﻼﺡ ﻟﻠﺘﺭﻤﻴﺯ:ﻟﻘﺩ ﺒﺭﻫﻨﺎ ،ﻤﻥ ﺨﻼل ﺍﻟﻨﺸﺎﻁ ،ﺃﻨﻪ :ﻤﻥ ﺍﺠل ﻜل ﻋﺩﺩ ﺼﺤﻴﺢ :nﺇﺼﻁﻼﺤﺎ exp(n)=en ،ﻨﻤﺩﺩ ﻫﺫﻩ ﺍﻟﻜﺘﺎﺒﺔ ﺇﻟﻰ ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ . x ﺍﺼﻁﻼﺡ: ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ ، xﻴﺭﻤﺯ ﺒﺎﻟﺭﻤﺯ exﺇﻟﻰ ﺍﻟﻌﺩﺩ ﺍﻟﺤﻘﻴﻘﻲ ﺍﻟﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ ﺼﻭﺭﺓ xﺒﺎﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ. ﺃﻱ :ﺍﺼﻁﻼﺤﺎ :ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ exp(x)=ex : x -ﺠـ-ﺍﺴﺘﻌﻤﺎل ﺤﺎﺴﺒﺔ ﻟﺘﻌﻴﻴﻥ ﻗﻴﻡ )ﻤﻘﺭﺒﺔ( ﻟﻠﺩﺍﻟﺔ expﻓﻲ ﺃﻏﻠﺒﻴﺔ ﺍﻟﺤﺎﺴﺒﺎﺕ ﺍﻟﻌﻠﻤﻴﺔ ﻭ ﻜﺫﻟﻙ ﺍﻟﺤﺎﺴﺒﺎﺕ ﺍﻟﺒﺎﻨﻴﺔ ،ﻟﻠﺤﺼﻭل ﻋﻠﻰ ﻗﻴﻤﺔ )ﻤﻘﺭﺒﺔ(ﻟﻠﻌﺩﺩ )eαﺤﻴﺙ α ﻋﺩﺩ ﺤﻘﻴﻘﻲ( ﺘﺴﺘﻌﻤل ﺍﻟﻠﻤﺴﺘﺎﻥ 2ndF ﻭ LNﻤﺜﻼ :ﻟﺤﺴﺎﺏ ﻗﻴﻤﺔ ﻤﻘﺭﺒﺔ ﻟﻠﻌﺩﺩ e 17ﺒﺎﺴﺘﻌﻤﺎل ﺤﺎﺴﺒﺔ ﻋﻠﻤﻴﺔ ﺍﻟﻤﺭﺍﺤل ﻤﻥ ﺍﻟﻴﺴﺎﺭ ﺇﻟﻰ ﺍﻟﻴﻤﻴﻥ ﺘﻜﻭﻥ ﻜﻤﺎ ﻴﻠﻲ:2ndF = ) ) LN ( √ ( 4 7 ﻴﻅﻬﺭ ﻋﻠﻰ ﺍﻟﺸﺎﺸﺔ 61,7507194 :
ﺨﻭﺍﺹ ﺃﻭﻟﻴﺔ ﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻤﻥ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ : * ﻤﻬﻤﺎ ﻴﻜﻭﻥ ﺍﻟﻌﺩﺩ ﺍﻟﺤﻘﻴﻘﻲ exp(x)، xﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ ﻤﻨﻪ(1)..... ex>0 : * ﻤﻥ ﺃﺠل xﻓﻲ ℜﻭ yﻓﻲ * y=exp(x):ℜ+ﻴﻌﻨﻲ ) x=ln(yﺇﺫﻥ : y=exﻴﻜﺎﻓﺊ )(2)...... x=ln(y* ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ xﺍﻟﻌﺩﺩ ﺍﻟﺤﻘﻴﻘﻲ ﺍﻟﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ yﺤﻴﺙ y=exp(x) :ﻴﺤﻘﻕ ln(y)=xﻤﻨﻪ: ln(exp(x))=xﺃﻱ .(3)...ln(ex)=x* ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ xﺇﺫﺍ ﻭﻀﻌﻨﺎ ) t=ln(xﻟﺩﻴﻨﺎ ،ﺒﺎﻻﻋﺘﻤﺎﺩ ﻋﻠﻰ ) x=et ،(2ﻭ ﺒﻤﺎ ﺃﻥ ) t=ln(xﻴﻜﻭﻥ )(4)...x=eln(x ﻤﻥ ) eln(1) : (4ﻭ eln(e)=eﺃﻱ e0=1ﻭ (5)... e1=e ﻭ ﻫﻜﺫﺍ ﺒﺭﻫﻨﺎ ﻋﻠﻰ ﺍﻟﺨﻭﺍﺹ ﺍﻟﺘﺎﻟﻴﺔ : ﺨﻭﺍﺹ: (1ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ .ex>0: x(2ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ xﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ (y=ex) :ﻴﻜﺎﻓﺊ )). (x=ln(y (3ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ . ln(ex)=x : x (4ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ . eln(x)=x:x ﺃﻤﺜﻠﺔ : -ﻟﻨﺤل ﻓﻲ ،ℜﺍﻟﻤﻌﺎﺩﻟﺔ (1).... ex = 2ﻭ ﺍﻟﻤﺘﺭﺍﺠﺤﺔ (2)... ex ≤ 7ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ ) (1ﻫﻲ ،ℜﻭ ﻜﺫﻟﻙ ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﻤﺘﺭﺍﺠﺤﺔ ) (2ﻫﻲ .ℜﻭ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ) (2ﺘﻜﺎﻓﺊ )ln(ex ) ≤ ln(7 ﻗﻴﻤﺔ xﻓﻲ :ℜ ﺘﻜﺎﻓﺊ )x ≤ ln(7 ) (1ﺘﻜﺎﻓﺊ )ln(e x ) = ln( 2ﻤﻨﻪ ﻤﺠﻤﻭﻋﺔ ﺤﻠﻭل ﺍﻟﻤﺘﺭﺍﺠﺤﺔ ) (2ﻫﻲ ﺘﻜﺎﻓﺊ )x = ln( 2 ﻤﻨﻪ ﻤﺠﻤﻭﻋﺔ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ) (1ﻫﻲ] )]− ∞; ln(7 } ){ ln( 2
ﻫﻲ ℜﻷﻥ: f )(x = ex ﺍﻟﻤﻌﺭﻓﺔ f ﺍﻟﺩﺍﻟﺔ ﺘﻌﺭﻴﻑ ﻤﺠﻤﻭﻋﺔ - ﺒﺎﻟﺩﺴﺘﻭﺭ ex + 1ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ ex : ℜﻤﻭﺠﻭﺩ ﻓﻲ * ℜ+ﻭ ﺒﺎﻟﺘﺎﻟﻲ exﻤﻭﺠﻭﺩ ﻓﻲ ℜﻭ ex>0ﻤﻨﻪ ex+1>1 ﻤﻨﻪ .ex+1≠0ﺃ( ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ gﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ ) g(x)=ln(2ex+3ﻫﻲ ℜﻷﻥ :ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ 2ex+3 ℜﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ ) ﻭ ﻤﻨﻪ ﺘﻭﺠﺩ ﻟﻪ ﺼﻭﺭﺓ ﺒﺎﻟﺩﺍﻟﺔ .(ln ﺨﻭﺍﺹ ﺠﺒﺭﻴﺔ ﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻤﺒﺭﻫﻨﺎﺕ: ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩﻴﻥ ﺤﻘﻴﻘﻴﻴﻥ aﻭ ،bﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺼﺤﻴﺢ :n )... ea+b=ea×eb(1ﺍﻟﺨﺎﺼﻴﺔ ﺍﻟﺠﺒﺭﻴﺔ ﺍﻷﺴﺎﺴﻴﺔ ﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ( 1 ( )ea (5، ea n = ena e(4، a−b = ea (3، e−a = 1 (2 ea = e2a eb ﺍﻟﺒﺭﻫﺎﻥ: ﻟﻴﻜﻥ aﻭ bﻋﺩﺩﻴﻥ ﺤﻘﻴﻘﻴﻴﻥ ﻭ ﻟﻴﻜﻥ nﻋﺩﺩﺍ ﺼﺤﻴﺤﺎ ﻤﻥ ﺨﻭﺍﺹ ﺍﻟﺩﺍﻟﺘﻴﻥ lnﻭ: exp(1ﻟﺩﻴﻨﺎ (*)....ln(ea+b)=a+b :ﻭ ) ln(eb×ea)=ln(ea)+ln(ebﻤﻨﻪ .(•)....ln(eb×ea)=a+b : ﻭ ﻤﻥ ﺍﻟﻤﺴﺎﻭﺘﻴﻥ )*( ﻭ )•( ﻭ ﺒﺎﻟﺘﻐﺫﻴﺔ )ln(ea+b)=ln(eb×ea ﻤﻨﻪ .ea+b=ea×eb ⎜⎛ln 1 ⎟⎞ = −a ﻤﻨﻪ ⎜⎛ln 1 = ⎟⎞ ) − ln(ea (2ﻟﺩﻴﻨﺎ ln(e-a)=-a :ﻭ ea ⎠ ea ⎝ ⎝ ⎠ e−a = 1 ﻤﻨﻪ ⎛⎜ln 1 ⎟⎞ = ) ln(e−a ﻤﻨﻪ ea ea ⎠ ⎝ﻤﻨﻪ ⎜⎜⎛⎝ln e a = ⎠⎟⎟⎞ a−b ﻤﻨﻪ ⎜⎜⎛⎝ln ea ) ⎞⎠⎟⎟ = ln(ea ) − ln(eb ﻭ ln(ea-b)=a-b : ﻟﺩﻴﻨﺎ (3 e b eb e. a−b = ea ﻋﻠﻴﻪ ﻭ ⎜⎛⎝⎜ln e a ⎟⎠⎞⎟ = ) ln(ea−b eb e b
(4ﻟﺩﻴﻨﺎ ln(ena)=na :ﻭ ) ln[(ea)n]=n.ln(eaﻤﻨﻪ ln[(ea)n]=naﻤﻨﻪ ) ln[(ea)n]=ln(enaﻭ ﻋﻠﻴﻪ .(ea)n=ena 1 1 ⎝⎜⎛ln ea ⎞⎟⎠ = 2 a ﻤﻨﻪ ⎜⎛⎝ln ea ⎠⎟⎞ = 2 ln(e a ) (5ﻟﺩﻴﻨﺎ : 1 ea ⎜⎜⎝⎛ln e 1 ⎞⎟ = ⎛⎝⎜ln ea ﻤﻨﻪ ⎠⎞⎟ ⎛⎜⎜⎝ln e 1 a ⎞⎟ = 1 a 2a ⎠⎟ 2 ⎠⎟ 2= e2a ﻭ ﻋﻠﻴﻪ ﻭ ﺃﻤﺜﻠﺔ ﺘﻁﺒﻴﻘﻴﺔ: -ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ e2 x+1 × e3 = e(2x+1)+3 ℜ = e2x+4 (= e1 2 )x+4 2 ﻤﻨﻪ :ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ ، ℜﻟﺩﻴﻨﺎ e2x+1 × e3 = ex+2 : -ﻟﻨﺤل ،ﻓﻲ ،ℜﺍﻟﻤﻌﺎﺩﻟﺔ (1)..... 5e2x+9ex-2=0 :ﺤﻴﺙ xﻫﻭ ﺍﻟﻤﺠﻬﻭل. ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﻤﻌﺎﺩﻟﺔ) (1ﻫﻲ ℜﻭ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ: ℜ ﺘﻜﺎﻓﺊ 5(ex)2+9(ex)-2=0 ﺒﻭﻀﻊ (1) X=ex :ﺘﺼﺒﺢ (2)....5X2+9X-2=0 ) (2ﻤﻌﺎﺩﻟﺔ ﻤﻥ ﺍﻟﺩﺭﺠﺔ ﺍﻟﺜﺎﻨﻴﺔ ﻤﻤﻴﺯﻫﺎ∆ ﺒﺤﻴﺙ .∆=121 1 ﺤﻼ ) (2ﻤﺎ X1ﻭ X2ﺤﻴﺙ X1 = 5 :ﻭ .X2=-2ﺍﻟﺨﻭﺍﺹ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ،ﻻ ﻴﻭﺠﺩ ﺃﻱ ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻭ ﻤﻥ ex = −2 ﺃﻭ ex 1 ﻤﻨﻪ ) (1ﺘﻜﺎﻓﺊ = 5 xﻴﺤﻘﻕ . ex = −2 x = ⎜⎛ln 1 ⎟⎞ ﺘﻜﺎﻓﺊ ex 1 ﻭ ﻋﻠﻴﻪ (1) :ﺘﻜﺎﻓﺊ ⎝ 5 ⎠ = 5 ﺘﻜﺎﻓﺊ )x = − ln(5 ﻤﻨﻪ ﻤﺠﻤﻭﻋﺔ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ) ( 1ﻫﻲ }). {-ln(5 -ﻟﻨﺤل ،ﻓﻲ ،ℜﺍﻟﻤﺘﺭﺍﺠﺤﺔ (2).... 5e2x-9ex-2≤0
ﻜﺜﻴﺭ ﺍﻟﺤﺩﻭﺩ 9X2-9X-2ﻴﺤﻠل ﺇﻟﻰ )5(X-X1)(X-X2 - 2 = 5⎜⎛ e x − 1 ⎟⎞ e x ⎝ ⎠5( )5e 2x - 9e x +2 ﻤﻨﻪ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ :ℜﻭ ﻟﻜﻲ ﻨﺤل ﺍﻟﻤﺘﺭﺍﺠﺤﺔ ) ،(2ﻨﺩﺭﺱ ﺇﺸﺎﺭﺓ 5e2x-9ex-2ﺤﺴﺏ ﻗﻴﻡ xﻓﻲ ℜﺃﻱ ﺇﺸﺎﺭﺓ ﺍﻟﺠﺩﺍﺀ ( )5⎜⎛ e x − 1 ⎟⎞ e x + 2 ⎠⎝ 5 ، e xﻨﻘﺎﺭﻥ ﻫﺫﺍ ﺍﻟﻔﺭﻕ ﻤﻊ .0 1 ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ ex>0 ،ℜﻤﻨﻪ 5(ex+2)>0ﻟﺩﺭﺍﺴﺔ ﺇﺸﺎﺭﺓ − 5). x = − ln(5 ﻭ ﻴﻜﺎﻓﺊ ⎞⎟ ln(e x ) = ln⎜⎛ 1 e xﻭ ﻴﻜﺎﻓﺊ 1 e xﻴﻜﺎﻓﺊ −1 =0 ⎠⎝5 = 5 5). x > − ln(5 ﻭ ﻴﻜﺎﻓﺊ ⎞⎟ ln(e x ) > ln⎜⎛ 1 exﻭ ﻴﻜﺎﻓﺊ > 1 e xﻴﻜﺎﻓﺊ 1 >0 ⎠⎝5 5 − 5). x < − ln(5 ﻭ ﻴﻜﺎﻓﺊ ⎟⎞ ln(e x ) < ln⎜⎛ 1 e xﻭ ﻴﻜﺎﻓﺊ 1 e xﻴﻜﺎﻓﺊ −1 <0 ⎠⎝5 < 5 5 ﻭ ﺍﻹﺸﺎﺭﺍﺕ ﺘﻠﺨﺹ ﻓﻲ ﺍﻟﺠﺩﻭل ﺍﻟﺘﺎﻟﻲ: x ∞- )-ln(5 ∞+ ﺇﺸﺎﺭﺓ )5(ex+2 + +⎜⎛ ex − 1 ⎞⎟ -+⎝ 5 ⎠ ﺇﺸﺎﺭﺓﺇﺸﺎﺭﺓ )(5e2x-9ex-2 -+ ﻤﻨﻪ :ﻤﺠﻤﻭﻋﺔ ﺤﻠﻭل ﺍﻟﻤﺘﺭﺍﺠﺤﺔ ) (2ﻫﻲ ])]-∞ ;-ln(5
ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻤﺒﺭﻫﻨﺔ: (1ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ .ℜ (2ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻫﻲ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻨﻔﺴﻬﺎ.* ﺒﻌﺒﺎﺭﺍﺕ ﺃﺨﺭﻯ :ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ ،xlexﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ،ℜﻫﻲ ﺍﻟﺩﺍﻟﺔ ،xlexﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ .ℜ ﻨﻘﺒل ﺒﺩﻭﻥ ﺒﺭﻫﺎﻥ ﺍﻟﺸﻁﺭ (1ﻤﻥ ﺍﻟﻤﺒﺭﻫﻨﺔ ﺍﻟﺴﺎﺒﻘﺔ. ﺍﻟﺒﺭﻫﺎﻥ ﻋﻠﻰ ﺍﻟﺸﻁﺭ:(2 ﺍﻟﺩﺍﻟﺔ expﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ .ℜ ﻭ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ . exp(x)>0 ، ℜﻤﻨﻪ ﻭﺤﺴﺏ ﺍﻟﻤﺒﺭﻫﻨﺔ ﺤﻭل ﻤﺸﺘﻘﺔ ﺩﺍﻟﺔ ﻤﻥ ﺍﻟﺸﻜل ) lno uﺃﻱ ﻤﻥ ﺍﻟﺸﻜل ]).(xlln[u(x ﺍﻟﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ f(x)=ln(exp(x)) :ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ،ℜ. = )f ′(x )exp′( x ﻭ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ f′′ﻤﻌﺭﻓﺔ ﻋﻠﻰℜ ﺒﺎﻟﺩﺴﺘﻭﺭexp(x) : ﻭ ﻟﻨﺎ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ f(x)=x، ℜﻤﻨﻪ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ ℜ . )exp′( x =1، ℜ ﻓﻲ x ﻗﻴﻤﺔ ﺘﻜﻭﻥ ﻤﻬﻤﺎ ﻤﻨﻪ f′′(x)=1 )exp(x ﻭ ﻋﻠﻴﻪ :ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ .exp′(x)=exp(x) :ℜ ﺍﺴﺘﻨﺘﺎﺠﺎﺕ: ﺒﻤﺎ ﺃﻥ ﺍﻟﺩﺍﻟﺔ expﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ℜﻓﺈﻨﻬﺎ ﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ .ℜﺒﻤﺎ ﺃﻥ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ expﻫﻲ ﺍﻟﺩﺍﻟﺔ expﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ expﻫﻲ ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ، ﻋﻠﻰ ، ℜﻟﻠﺩﺍﻟﺔ . exp ﻟﺩﻴﻨﺎ :ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ exp′(x)=ex :ℜﻭ ex>0 ﻤﻨﻪ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ exp′(x)>0 ℜﻤﻨﻪ ﺍﻟﺩﺍﻟﺔ expﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ .ℜ
ﻤﺒﺭﻫﻨﺔ: ﺍﻟﺩﺍﻟﺔ ) xlexﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ (ℜﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ.ℜ ﺍﻟﺩﺍﻟﺔ ) xlexﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ (ℜﻫﻲ ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻋﻠﻰ ℜﻟﻠﺩﺍﻟﺔ ) xlexﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ . (ℜ ﻤﺒﺭﻫﻨﺔ : ﺍﻟﺩﺍﻟﺔ ) xlexﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ( ℜﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ .ℜ ﻤﺜﺎﻻﻥ: f )(x = e x + 2x : ،ℜﺒﺎﻟﺩﺴﺘﻭﺭ ﻋﻠﻰ ﺍﻟﻤﻌﺭﻓﺔ ﺍﻟﺩﺍﻟﺔ f ﻟﺘﻜﻥ - 2e x + 1 ℜﺒﺎﻟﺩﺴﺘﻭﺭﻴﻥ : ﺃﻴﻥ uﻭ vﺍﻟﺩﺍﻟﺘﺎﻥ ﺍﻟﻤﻌﺭﻓﺘﺎﻥ ﻋﻠﻰ f u ﻟﺩﻴﻨﺎ = : v u(x)=ex+2xﻭ .v(x)=2ex+1ﺍﻟﺩﺍﻟﺔ uﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ℜﻭ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ . u′(x)=ex+2 : ℜﺍﻟﺩﺍﻟﺔ vﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ℜﻭ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ . v′(x)=2ex : ℜ ﻭ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ v(x)≠0 ،ℜﻤﻨﻪ ﺍﻟﺩﺍﻟﺔ fﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ℜﻭ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ f ′ﻤﻌﺭﻓﺔ ﻋﻠﻰ ،ℜﺒﺎﻟﺩﺴﺘﻭﺭ : f )′( x = )v(x).u′(x) − u(x).v′(x (v( x)) 2f )′(x = (2e x + 1).(e x + 2) − (e x + 2x).2e x ﺃﻱ : (2e x + 1)2ﻭ ﺒﻌﺩ ﺇﻨﺠﺎﺯ ﺍﻟﺤﺴﺎﺒﺎﺕ ) ﻤﻊ ﺍﻷﺨﺫ ﺒﺎﻻﻋﺘﺒﺎﺭ ex.ex=(ex)2ﻤﻨﻪ (ex.ex=e2xﺍﻟﺩﺍﻟﺔ uﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ℜﻭ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ . u′(x)=ex+2 : ℜ f )′( x = 5e x − 4xe x + 2 (2e x +1) 2 -ﺍﻟﺩﺍﻟﺔ gﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ * ،ℜ+ﺒﺎﻟﺩﺴﺘﻭﺭ g (x) = 3ex + x2 + 1 : x
ﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ ﺍﻟﻤﺠﺎل [∞ ]0 ;+ﻤﻨﻪ ﻫﻲ ﺘﻘﺒل ﺩﻭﺍﻻ ﺃﺼﻠﻴﺔ ﻋﻠﻰ [∞ ]0 ;+ﻭ ﺍﻟﺩﺍﻟﺔ Gﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ G ( x ) = 3 e x +ﻫﻲ ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ x3 ) + ln( x ﺒﺎﻟﺩﺴﺘﻭﺭ: [∞]0 ;+ 3 gﻋﻠﻰ ﺍﻟﻤﺠﺎل [∞. ]0 ;+ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﺩﺍﻟﺔ ﻤﻥ ﺍﻟﺸﻜل )xleu(x ﻤﺒﺭﻫﻨﺔ:ﻟﻴﻜﻥ Iﻤﺠﺎل ﻭ ﻟﺘﻜﻥ uﺩﺍﻟﺔ ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻔﻬﺎ ﺘﺤﺘﻭﻱ ﺍﻟﻤﺠﺎل . I ﺇﺫﺍ ﻜﺎﻨﺕ ﺍﻟﺩﺍﻟﺔ uﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﺍﻟﻤﺠﺎل . I ﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ f(x)=eu(x) :ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﺍﻟﻤﺠﺎل Iﻭ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ f ′ﺒﺤﻴﺙ ،ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ :I ).f ′(x)=u′(x).eu(x ﺍﻟﺒﺭﻫﺎﻥ:ﻭ ﻤﻌﻁﻴﺎﺕ ﺍﻟﻨﺹ ﺍﻟﺴﺎﺒﻕ ﻭ ﻓﺭﻀﻴﺘﻪ ﺴﺎﺌﺩﺓ : ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻱ f(x)=eu(x) ، I ))=exp(u(x ﻤﻨﻪ)f (x) = (expo u)(xﻭ ﺍﻟﺩﺍﻟﺔ uﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ Iﻭ ﺍﻟﺩﺍﻟﺔ expﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ℜﻭ ﻤﻨﻪ ﻤﻬﻤﺎ ﻴﻜﻭﻥ ﺍﻟﻌﻨﺼﺭ x0ﻤﻥ ، Iﺍﻟﺩﺍﻟﺔ expﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ ) u(x0ﻤﻨﻪ ﻭ ﺤﺴﺏ ﺍﻟﻤﺒﺭﻫﻨﺔ ﺤﻭل ﺍﺸﺘﻘﺎﻕ ﺩﺍﻟﺔ ﻤﺭﻜﺒﺔ ﺍﻟﺩﺍﻟﺔﺍﻟﻤﺭﻜﺒﺔ ) (expo uﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﺍﻟﻤﺠﺎل Iﻭ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ (expo u)′ﺒﺤﻴﺙ :ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ : I)(expo u)′ = exp′[u(x)]× u′(x )= exp[u(x)]× u′(xﻤﻨﻪ ﺍﻟﺩﺍﻟﺔ fﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ Iﻭ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ f ′ﺒﺤﻴﺙ :ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ f :I )′(x)=u′(x).eu(x
ﻤﺜﺎل: 1ﻟﺘﻜﻥ fﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ﺍﻟﻤﺠﺎل[∞ ] 0;+ﺒﺎﻟﺩﺴﺘﻭﺭf (x) = ln(x) + e 2x × e x × e x : 2x+1+ xﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ [∞f (x) = ln(x) + e x :] 0;+ﻭ ﺒﻭﻀﻊ u(x) = 2x + 1 + x :ﺍﻟﺩﺍﻟﺔ uﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ [∞ ] 0;+ﻭ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ u′ x )u′( x = 2− 1 + 1 ﺒﺤﻴﺙ x2 2xﻤﻨﻪ ﺍﻟﺩﺍﻟﺔ fﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ [∞ ] 0;+ﻭ ﺍﻟﺩﺍﻟﺔ lnﻜﺫﻟﻙ ﻤﻨﻪ :ﺍﻟﺩﺍﻟﺔ fﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﺍﻟﻤﺠﺎل [∞ ] 0;+ﻭ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﻘﺔ f ′ﻤﻌﺭﻓﺔ ﻋﻠﻰ [∞ ] 0;+ﺒﺎﻟﺩﺴﺘﻭﺭ: )′( x 1 + ⎛⎜ 2 1 1 ⎟⎞e 2 x + 1 + x x ⎝ x2 xf = − + ⎠2 x ﺍﺴﺘﻨﺘﺎﺝ: ﻤﺒﺭﻫﻨﺔ: ﻟﻴﻜﻥ Iﻤﺠﺎﻻ ﻭ ﻟﺘﻜﻥ uﺩﺍﻟﺔ ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻔﻬﺎ ﺘﺤﺘﻭﻱ ﺍﻟﻤﺠﺎل . I ﺇﺫﺍ ﻜﺎﻨﺕ ﺍﻟﺩﺍﻟﺔ Uﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﺍﻟﻤﺠﺎل .I ﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ Gﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ﺍﻟﻤﺠﺎل Iﺒﺎﻟﺩﺴﺘﻭﺭ G(x)=eu(x) :ﻫﻲﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ،ﻋﻠﻰ ﺍﻟﻤﺠﺎل ،Iﻟﻠﺩﺍﻟﺔ gﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭg(x)=u′(x).eu(x) : ﺍﻟﺒﺭﻫﺎﻥ: ﻭ ﻤﻌﻁﻴﺎﺕ ﺍﻟﻨﺹ ﺍﻟﺴﺎﺒﻕ ﻭ ﻓﺭﻀﻴﺘﻪ ﺴﺎﺌﺩﺓ ،ﺍﻟﺩﺍﻟﺔ Gﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ Iﻭ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻑ .G′(x)=g(x)،I ) ﺒﺘﻁﺒﻴﻕ ﺍﻟﻤﺒﺭﻫﻨﺔ ﺤﻭل ﺍﺸﺘﻘﺎﻕ ﺩﺍﻟﺔ ﻤﻥ ﺍﻟﺸﻜل)( xleu(x ﻤﻨﻪ Gﻫﻲ ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ ،gﻋﻠﻰ ﺍﻟﻤﺠﺎل . Iﻤﺜﺎل:ﻟﺘﻜﻥ fﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ، ℜﺒﺎﻟﺩﺴﺘﻭﺭ f (x) = (x + 1)e(x2 ) × e 2x :ﻻ ﻨﺤﺴﻥ ﺘﻌﻴﻴﻥ ﺩﺍﻟﺔ ﺃﺼﻠﻴﺔ ﻟﺠﺩﺍﺀ ﻟﺫﺍ ﻨﻘﻭﻡ ﺒﺘﺤﻭﻴل ﻋﺒﺎﺭﺓ ). f(x ﻤﻥ ﺃﺠل xﻓﻲ . f (x) = (x + 1)e(x2 +2x) ،ℜ ﻟﻨﻀﻊ u(x)=x2+2x :ﻟﺩﻴﻨﺎ u′(x)=2x+2ﻤﻨﻪ ). u′(x)=2(x+1
= )f (x )1 u′(x).e u(x = ) (x + 1ﻭ ﻫﻜﺫﺍ : )1 u′(x ﻤﻨﻪ : 2 2 1 ﻭ ﺍﻟﺩﺍﻟﺔ ) xleu(xﻫﻲ ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ) xlu′(x).eu(xﻋﻠﻰ ،ℜﻭ 2ﻋﺩﺩ ﺜﺎﺒﺕ ﻤﻨﻪ ﺍﻟﺩﺍﻟﺔ ﻋﻠﻰ.ℜ f ﻟﻠﺩﺍﻟﺔ ﺍﻷﺼﻠﻴﺔ ﺍﻟﺩﻭﺍل ﻤﻥ ﻭﺍﺤﺩﺓ ﻫﻲ )F ( x = 1 )e u( x ﺒﺎﻟﺩﺴﺘﻭﺭ: ℜ ﻋﻠﻰ ﺍﻟﻤﻌﺭﻓﺔ F 2ﺍﻷﺼﻠﻴﺔ ﺍﻟﺩﻭﺍل ﻤﻥ ﻭﺍﺤﺩﺓ ) F (xﻫﻲ = 1 ،ﺒﺎﻟﺩﺴﺘﻭﺭ )e (x2 +2x ℜ ﻋﻠﻰ ﺍﻟﻤﻌﺭﻓﺔ F ﺍﻟﺩﺍﻟﺔ ﻋﻠﻴﻪ: ﻭ 2 ﻟﻠﺩﺍﻟﺔ fﻋﻠﻰ .ℜLﻟﺘﻌﻴﻴﻥ ﺩﺍﻟﺔ ﺃﺼﻠﻴﺔ ﻟﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ fﻟﻤﺘﻐﻴﺭ ﺤﻘﻴﻘﻲ xﺤﻴﺙ ﻋﺒﺎﺭﺓ ) f(xﺘﺸﻤل \"ﻋﻨﺎﺼﺭ\" ﻤﻥ ﺍﻟﺸﻜل) ،eu(xﻨﻌﻴﻥ ) u′(xﻭ ﻨﺤﺎﻭل ﺇﺒﺭﺍﺯ ﺍﻟﺠﺩﺍﺀ ) u′(x).eu(xﻭ)ﺃﻭ( ﻨﻁﺒﻕ ﺍﻟﻨﺘﺎﺌﺞ ﺍﻟﻌﺎﻤﺔ ﺤﻭل ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ. ﻨﻬﺎﻴﺎﺕ ﻗﺎﻋﺩﻴﺔ ﻤﻥ ﺘﻌﺭﻴﻑ ﺍﻟﻌﺩﺩ ﺍﻟﻤﺸﺘﻕ ﻟﺩﻴﻨﺎlim ⎜⎛ x → exp( 0 + x ) − exp( 0) ⎟⎞ : ⎠ 0⎝ x ﻭ exp′(x)=e0ﻤﻨﻪ exp′(0)=1 (1)..... li0m⎝⎜⎛⎜ x e x − 1 ⎟⎟⎞⎠ x → : ﻋﻠﻴﻪ ﻭ ﻭ ﻤﻥ ﺃﺠل xﻤﻥ *( )ex = ex −1 × x +1 : ℜ x( ):ﺍﻟﻨﻬﺎﻴﺎﺕ ﺤﻭل ﺍﻟﻤﺒﺭﻫﻨﺎﺕ ﺒﺎﺴﺘﻌﻤﺎل )(2 ﻭ )(1 ﻤﻥ ﻭ (2)... lim →x x ﻭ ﻟﺩﻴﻨﺎ = 0 : 0 ⎜⎛ (e x − 1)× x + 1 ⎞⎟ ⎜ ⎟ lim ⎜ x → 1 4x42 443 ⎟ = 1× 0 +1 0 ⎟⎟⎠ ⎜⎝⎜ ( )(I).... lim x → ex ﻭ ﻋﻠﻴﻪ = 1 0
ex−a = ex ﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ،ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ ،ℜ eaﻤﻥ )( )(Ilim x → ex ﻤﻨﻪ ex = ea × ex−aﻭ ﻟﺩﻴﻨﺎ lim(x → x − a) = 0ﻭ= 1 0 aﻤﻨﻪ ﻭ ﺤﺴﺏ ﺍﻟﻤﺒﺭﻫﻨﺔ ﺤﻭل ﻨﻬﺎﻴﺔ ﺩﺍﻟﺔ ﻤﺭﻜﺒﺔ ( )lim x → ex−a = 0a ⎝⎜⎛⎜liam x → e1a2.e3x−a ⎟⎠⎟⎞ = ea ×1 ﻋﻠﻴﻪ: ﻭ ex ﺇﺫﻥ ( )(α) lim x → ex = ea : a ﻟﺘﻜﻥ fﻭ gﺍﻟﺩﺍﻟﺘﻴﻥ ﺍﻟﻤﻌﺭﻓﺘﻴﻥ ﻋﻠﻰ ﺍﻟﻤﺠﺎل [∞ [1 ;+ﺒﺎﻟﺩﺴﺘﻭﺭﻴﻥ : f(x)=ex-2xﻭ g(x)=ex-x2 ﺍﻟﺩﺍﻟﺘﺎﻥ fﻭ gﻗﺎﺒﻠﺘﺎﻥ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﺍﻟﻤﺠﺎل [∞.[1 ;+ -ﻤﻥ ﺃﺠل xﻓﻲ [∞ f ′(x)=ex-2 [1 ;+ﻭ x≥1ﻤﻨﻪ .ex≥e1 )ﻷﻥ ﺍﻟﺩﺍﻟﺔ expﻤﺘﺯﺍﻴﺩﺓ ﻋﻠﻰ (ℜﻤﻨﻪ ex-2≥e-2ﻭ e-2>0ﻤﻨﻪ . f ′(x)>0ﻤﻨﻪ ﺍﻟﺩﺍﻟﺔ fﻤﺘﺯﺍﻴﺩﺓ ﻋﻠﻰ [∞[1 ;+ ﻤﻥ ﺃﺠل ﻜل ﻋﻨﺼﺭ xﻤﻥ [∞ x≥1 : [1 ;+ﻤﻨﻪ ) f(x)≥f(1ﻤﻨﻪ : f(x)≥e-2ﻤﻨﻪ .f(x)>0-ﻤﻥ ﺃﺠل ﻜل ﻋﻨﺼﺭ xﻤﻥ [∞ g′(x)=ex-2x : [1 ;+ﻤﻨﻪ ) g′(x)=f(xﻤﻨﻪ g′(x)>0ﻤﻨﻪ ﺍﻟﺩﺍﻟﺔ g ﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ [∞.[1 ;+ -ﻤﻥ ﺃﺠل ﻜل ﻋﻨﺼﺭ xﻤﻥ [∞ x≥1 ، [1 ;+ﻤﻨﻪ ) g(x)≥g(1ﻤﻨﻪ g(x)≥e-1 ﻤﻨﻪ g(x)>0ﻤﻨﻪ ex-x2>0 ﻭ ﻋﻠﻴﻪ ﻤﻥ ﺃﺠل xﻓﻲ [∞(•)..... ex>x2 : [1 ;+ ﻭ ﻟﺩﻴﻨﺎ ( )(••) lim x → x2 = +∞ : ∞+
ﻤﻥ )•( ﻭ )••( ﻭ ﺤﻭل ﺍﻟﻤﺒﺭﻫﻨﺎﺕ ﺤﻭل ﺍﻟﻨﻬﺎﻴﺎﺕ ﺒﺎﻟﻤﻘﺎﺭﺒﺔ : ∞(β) lim(x → ex ) = + ∞+ ﻭ ﻤﻥ)•( ﻤﻥ ﺃﺠل xﻓﻲ [∞(•••) ex > x [1 ;+ x ﻭ ∞(••••) lim(x → x) = + ∞+ﻭ ﻤﻥ )•••( ﻭ)••••( ﻭ ﺤﺴﺏ ﺍﻟﻤﺒﺭﻫﻨﺎﺕ ﺤﻭل ﺍﻟﻨﻬﺎﻴﺎﺕ ﺒﺎﻟﻤﻘﺎﺭﺒﺔ : ) (γ ∞lim⎜⎛ x → ex ⎞⎟ = + ⎠ ⎝+∞ x ex = 1 ﻤﻥ ﺃﺠل xﻓﻲ ،ℜ e−xﻭ ﻟﺩﻨﻴﺎ lim(x → −x) = +∞ :ﻭ ∞ lim x → ex = +ﻤﻨﻪ) (∞+∞ − lim⎛⎜ x 1 ⎞⎟ ∞⎝− e−x ⎠ﻋﻠﻴﻪ) (ﻭ → = 0 ﻤﻨﻪ lim x → e−x ∞= + ∞− ex (δ) lim(x → ex ) = 0 ∞− xe x = ⎜⎛ −1 ⎞⎟ ﻤﻨﻪ xex = x ﻤﻥ ﺃﺠل xﻓﻲ *: ℜ e−x e−x ⎠⎝−x⎛⎜⎜⎝ ∞( )li+mex⎞⎟⎟⎠x → x = ∞+ lim x → −xﻭ ﻭ ﻟﻨﺎ = +∞ : ∞− → li−m∞ ⎝⎜⎛⎜ x e−x ⎟⎠⎞⎟ = ∞+ ﻤﻨﻪ −x
)( )(ζ ⎜⎛ −1 ⎞⎟lim x → xex =0 → l−im∞⎜⎜ x e−x ⎟ ∞− ﻋﻠﻴﻪ ﻭ ⎟ = 0 ﻤﻨﻪ ⎠⎟ ⎝⎜ − x xex ﻭ ﻫﻜﺫﺍ ﻟﻘﺩ ﺒﺭﻫﻨﺎ ﻋﻠﻰ ﺍﻟﻤﺒﺭﻫﻨﺎﺕ ﺍﻟﺘﺎﻟﻴﺔ: ﻤﺒﺭﻫﻨﺎﺕ : ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ ( )lim x → ex = ea : a a ( )lim x → ex ∞= + ∞+ ( )lim x → ex =0 ∞− l+im∞⎜⎝⎛⎜ x → ex ⎞⎠⎟⎟ = ∞+ x ( )lim x → xe x =0 ∞− ﺃﻤﺜﻠﺔ : = )f (x ex +5 ﻟﺘﻜﻥ fﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: 2e x −1 Dfﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ fﻫﻲ ﻤﺠﻤﻭﻋﺔ ﺍﻷﻋﺩﺍﺩ ﺍﻟﺤﻘﻴﻘﻴﺔ xﺍﻟﺘﻲ ﺘﺤﻘﻕ . 2ex-1≠0ln(e x ) = ⎜⎛ln 1 ⎞⎟ ﻴﻜﺎﻓﺊ ex = 1 ﻭ ﻟﺩﻴﻨﺎ 2ex-1 :ﻴﻜﺎﻓﺊ ⎝ 2 ⎠ 2 ﻭ ﻴﻜﺎﻓﺊ x = − ln 2ﻤﻨﻪ } Df=ℜ-{-ln2ﺃﻱ [∞]-∞ ;-ln2 ;[∪]-ln2 ;+) ln(e x = ⎛⎜ln 1 ⎞⎟ ﻤﻨﻪ lim( x → )ex = 0 ﻟﺩﻴﻨﺎ -ﻭ ⎝ 2 ⎠ ∞−lim(x → ex + )5 = 11 ﻭ lim( x → 2e x )− 1 = 0- 2−ln 2 −ln 2
ﻴﻌﻨﻲ ) ln(ex > ⎛⎜ln 1 ⎞⎟ ﻴﻌﻨﻲ ex > 1 ﻨﺩﺭﺱ ﺇﺸﺎﺭﺓ 2ex-1 ⎝ 2 ⎠ 2 2ex-1=0ﻴﻌﻨﻲ 2ex-1>0 ، x=-ln2ﻴﻌﻨﻲ x > − ln 2 ﻭ ﺒﺎﻟﺘﺎﻟﻲ 2ex-1<0ﻴﻜﺎﻓﺊ x<-ln2 ﻤﻨﻪ ﺍﻹﺸﺎﺭﺍﺕ ﺘﻠﺨﺹ ﻓﻲ ﺍﻟﺠﺩﻭل: x -∞ -ln2 ∞+ ﺇﺸﺎﺭﺓ - + 2ex-1 lim f ∞= − ﻤﻨﻪ : −ln 2− ∞lim f = + −ln 2+-ﻋﻨﺩ ∞ ،+ﻨﻬﺎﻴﺔ fﻫﻲ ،ﻓﻲ ﺍﻟﻭﻫﻠﺔ ﺍﻷﻭﻟﻰ ،ﺤﺎﻟﺔ ﻋﺩﻡ ﺘﻌﻴﻴﻥ ) ﻨﻬﺎﻴﺔ ﺍﻟﺒﺴﻁ ﻫﻲ ∞ +ﻭ ﻜﺫﻟﻙ ﻨﻬﺎﻴﺔ ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ ، ℜ ﺍﻟﻤﻘﺎﻡ(. (( ))f )(x = 1+ 5 ﻤﻨﻪ = )f (x ex 1+ 5 2− ex ex 1 1 ex ex 2− ex lim( x → 5 ) = 0 ﻤﻨﻪ ) lim(x → ex ∞= + : ﻟﺩﻴﻨﺎ ﻭ ex ∞+ ∞+ lim( x → 1 ) = 0 ﻭ ∞+ ex lim f = 1 ﻤﻨﻪ: 2 ∞+ ﻟﺘﻜﻥ gﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ℜﺒﺎﻟﺩﺴﺘﻭﺭ g(x)=(x+1).ex+2 : ﻟﺩﻴﻨﺎ lim(x → ex ) = +∞ :ﻭ ∞ lim(x → x +1) = +ﻤﻨﻪ ∞+∞ +
∞. lim g = + ∞+ ﻤﻥ ﺃﺠل xﻓﻲ g(x)=xex+ex+2 :ℜﻭ lim(x → xex ) = 0 ، lim(x → ex ) = 0ﻤﻨﻪ lim g = 2∞−∞ − ∞−ﺠﺩﻭل ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻭ ﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ -ﻤﻥ ﺍﻟﻨﺘﺎﺌﺞ ﺤﻭل ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻭ ﺍﺘﺠﺎﻩ ﺘﻐﻴﺭﻫﺎ∞x - ﻭ ﻨﻬﺎﻴﺎﺘﻬﺎ ﻴﻜﻭﻥ ﺠﺩﻭل ﺘﻐﻴﺭﺍﺘﻬﺎ ﻜﻤﺎ ﻴﻠﻲ: ∞+ex ∞+ 0 -ﻟﻴﻜﻥ ) (Cfﺍﻟﻤﻨﺤﻨﻲ ﺍﻟﻤﻤﺜل ﻟﻠﺩﺍﻟﺔ ) xlexﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ (ℜ* ﻟﺩﻴﻨﺎ lim(x → ex ) = 0 :ﻤﻨﻪ ﺍﻟﻤﺴﺘﻘﻴﻡ ﺫﻭ ﺍﻟﻤﻌﺎﺩﻟﺔ ) y=0ﺃﻱ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﻔﻭﺍﺼل( ∞− ﻫﻭ ﻤﺴﺘﻘﻴﻡ ﻤﻘﺎﺭﺏ ﻟﻠﻤﻨﺤﻨﻲ) (Cfﺒﺠﻭﺍﺭ ∞.- * ﺍﻟﻨﻘﻁﺔ ) C(0 ;1ﺘﻨﺘﻤﻲ ﺇﻟﻰ ) (Cfﻭ ﺇﺫﺍ ﺴﻤﻴﻨﺎ ) (d′ﺍﻟﻤﻤﺎﺱ ﻟﻠﻤﻨﺤﻨﻲ ) (Cfﻋﻨﺩ Cﻟﺩﻴﻨﺎ : ) (d′) :y=exp′(0)(x-0)+exp(0ﺃﻱ . (d′) :y=x+1 * ﺍﻟﻨﻘﻁﺔ ) D(1 ;eﺘﻨﺘﻤﻲ ﺇﻟﻰ ) (Cfﻭ ﺇﺫﺍ ﺴﻤﻴﻨﺎ ) (d″ﺍﻟﻤﻤﺎﺱ ﻟﻠﻤﻨﺤﻨﻲ ) (Cfﻋﻨﺩ Dﻟﺩﻴﻨﺎ ) (d″) :y=exp′(1).(x-1)+exp(1ﺃﻱ y=e(x-1)+e ﻤﻨﻪ (d″) :y=e.xﻤﻨﻪ ) (d″ﻴﺸﻤل ﺍﻟﻨﻘﻁﺔ 0ﻤﺒﺩﺃ ﺍﻟﻤﻌﻠﻡ .
ﻭ ﻤﻨﻪ ﺍﻟﺸﻜل: y 4 ) 3 ( Cf D 2 1C →j-4 -3 -2 -1 0 →i 1 2 3 4 x)'( d (d'') -1) (Cfﺍﻟﻤﻨﺤﻨﻲ ﺍﻟﻤﻤﺜل ﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﺒﺎﻟﻨﺴﺒﺔ ﺇﻟﻰ ﺍﻟﻤﻌﻠﻡ )(o;i; jﺍﻟﺘﺯﺍﻴﺩ ﺍﻟﻤﻘﺎﺭﻥ ﻟﻠﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﻭ ﺍﻟﺩﻭﺍل ﻗﻭﻯ ﻟﻴﻜﻥ nﻋﺩﺩﺍ ﻁﺒﻴﻌﻴﺎ ﻏﻴﺭ ﻤﻌﺩﻭﻡ. ﻟﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺘﻴﻥ fﻭ gﺍﻟﻤﻌﺭﻓﺘﺎﻥ ﺒﺎﻟﺩﺴﺘﻭﺭﻴﻥ: g(x) = xn.ex ﻭ f (x) = ex xn ﺍﻟﻬﺩﻑ ﻤﻥ ﻫﺫﻩ ﺍﻟﻔﻘﺭﺓ ﻫﻭ ﺤﺴﺎﺏ ﺍﻟﻨﻬﺎﻴﺘﻴﻥ lim fﻭ l im g ∞−∞ + ﻫﻤﺎ ﻓﻲ ﺍﻟﻭﻫﻠﺔ ،ﺤﺎﻟﺘﺎ ﻋﺩﻡ ﺘﻌﻴﻴﻥ ﻷﻥ :
lim(x → ex ) = 0 ﻭ lim(x → ex ) = +∞ −∞ +∞+∞ ﻫﻲlim(x → xn ) lim(x → xn ) = +∞ −∞ +∞n ﺤﺴﺏ ﺸﻔﻌﻴﺔ-∞ ﺃﻭ ( )x 1 x.n f (x) = enf (x) = e x ﻤﻨﻪ xn : ℜ* ﻓﻲx ﻤﻥ ﺃﺠل- xn ﻨﻘﻭﻡ ﺒﺎﻟﺘﺤﻭﻴلlim⎜⎛ X → e X ⎟⎞ ﻭ ﻗﺼﺩ ﺍﻻﻗﺘﺭﺍﺏ ﻤﻥ ﺍﻟﻭﻀﻊ f (x) = ⎛⎜ x ⎟⎞n ﻤﻨﻪ ⎝+∞ X ⎠ ⎜⎝ ⎟⎠ ex x f (x) = ⎛⎜ x ⎟⎞n ﺍﻟﺘﺎﻟﻲ ⎜ ⎟ ⎝ en ⎠ xn×n.ﺜﺎﺒﺕ ﻤﻭﺠﺏ ﺘﻤﺎﻤﺎ 1 ﻭ ﻟﺩﻴﻨﺎ f (x) = ⎛⎜ x ⎟⎞n × ⎜⎛ 1 ⎞⎟ ﻤﻨﻪ nn ⎜ ⎟ ⎝ nn ⎠ ex x ⎝ n⎠ ﻤﻨﻪlim⎜⎛ x → ex ⎟⎞ = +∞ lim⎛⎜ x → x ⎟⎞ = +∞ ﻭ⎝+∞ x ⎠ ⎝+∞ n ⎠ li+m∞ ⎛⎜⎜ x → x ⎞⎟ = +∞ ⎟ en n ⎝ x⎠ lim f = +∞ ﻤﻨﻪ +∞
)g(x = x .en 1.x.n = ⎛⎜ x.e x ⎟⎞n -ﻤﻥ ﺃﺠل xﻓﻲ :ℜ n x ⎠⎝= ⎛⎜ x x ⎞⎟n = ⎜⎛ nn x x ⎟⎞n .n..e x ..e x ⎠ ⎝n ⎠ ⎝n ﻭ ﻟﺩﻴﻨﺎ ∞ lim⎜⎛ x → x ⎞⎟ = −ﻭ ( )lim x → xex = 0 ⎠ −∞ −∞ ⎝ n lim⎜⎛ x → x .e x ⎟⎞ = 0 ﻤﻨﻪ n ⎠ −∞ ⎝ n ﻤﻨﻪ lim g = 0 ∞− ﻭ ﻫﻜﺫﺍ ﻟﻘﺩ ﺒﺭﻫﻨﺎ ﻋﻠﻰ ﻤﺒﺭﻫﻨﺔ. ﻤﺒﺭﻫﻨﺔ :lim(x → xn.ex ) = 0 ﻟﻴﻜﻥ nﻋﺩﺩﺍ ﻁﺒﻴﻌﻴﺎ ﻏﻴﺭ ﻤﻌﺩﻭﻡ. ∞− ∞lim⎜⎛ x → ex ⎞⎟ = + ⎠ +∞ ⎝ xn ﺤﻭﺼﻠﺔ ﻨﺘﺎﺌﺞ،ﻤﻼﺤﻅﺔ:ﻟﻴﻜﻥ nﻋﺩﺩﺍ ﻁﺒﻴﻌﻴﺎ ﻏﻴﺭ ﻤﻌﺩﻭﻡ ﺍﻟﺩﺍﻟﺔ ) xlxnﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ (ℜﺘﺴﻤﻰ \" ﺍﻟﺩﺍﻟﺔ ﻗﻭﺓ ﺫﺍﺕ ﺍﻷﺱ \"n ﻟﻤﺎ xﻴﺅﻭل ﺇﻟﻰ ∞:+ ﻟﻤﺎ ﻴﺅﻭل xﺇﻟﻰ 0ﺒﻘﻴﻡ ﻤﻭﺠﺒﺔ ﺘﻤﺎﻤﺎ: xnﻴﺅﻭل ﺇﻟﻰ ∞ +ﻭ exﻴﺅﻭل ﺇﻟﻰ ∞.+ﻷﻭل Xﻴﺅﻭل ﺇﻟﻰ 0ﻭ ) ln(xﻴﺅﻭل ﺇﻟﻰ ∞-ﻷﻭل ﻭﻫﻠﺔ ﻨﻬﺎﻴﺔ ﺍﻟﺠﺩﺍﺀ ) xn.ln(xﻫﻲ ﺤﺎﻟﺔ ﻋﺩﻡ ex ﻭﻫﻠﺔ ،ﻨﻬﺎﻴﺔ ﺤﺼل ﺍﻟﻘﺴﻤﺔ . xn ﺘﻌﻴﻴﻥ.
ﻋﺩﻡ ﺤﺎﻟﺔ 1 × ex ﺃﻱ ﻨﻬﺎﻴﺔ ﺍﻟﺠﺩﺍﺀ و ﺑﻌﺪ إزاﻟﺔ ﺣﺎﻟﺔ ﻋﺪم اﻟﺘﻌﻴﻴﻦ ،وﺟﺪﻧﺎ أن xnﻫﻲ ) xnln(xﻳﺆول إﻟﻰ0 ﺘﻌﻴﻴﻥ . و 0هﻮ ﻧﻬﺎﻳﺔ )(xlxn إذن ‘ xnﻳﺘﻔﻮق’ ﻋﻠﻰ××).ln(xﻭ ﺒﻌﺩ ﺇﺯﺍﻟﺔ ﺤﺎﻟﺔ ﻋﺩﻡ ﺍﻟﺘﻌﻴﻴﻥ ،ﻭﺠﺩﻨﺎ ﺃﻥ ﻟﻤﺎ ﻳﺆول xإﻟﻰ ∞+ Xnﻳﺆول إﻟﻰ ∞ +و ) ln(xﻳﺆول إﻟﻰ ∞+ ex ﻷول وهﻠﺔ ،ﻧﻬﺎﻳﺔ ﺣﺎﺻﻞ اﻟﻘﺴﻤﺔ xnﻴﺅﻭل ﺇﻟﻰ ∞+ ﻭ ∞ +ﻫﻲ ﻨﻬﺎﻴﺔ ) . (x → ex )ln(x أي ﻧﻬﺎﻳﺔ اﻟﺠﺪاء xn ﺇﺫﻥ ' exﻴﻔﻭﻕ' ﻋﻠﻰ ×× xn ) 1 .ln(xهﻲ ﺣﺎﻟﺔ ﻋﺪم اﻟﺘﻌﻴﻴﻦ. xn ﻟﻤﺎ ﻴﺅﻭل ﺇﻟﻰ ∞:- Xnﻴﺅﻭل ﺇﻟﻰ ∞ +ﺃﻭ ﺇﻟﻰ ∞ -ﻥ ﺤﺴﺏ ﺸﻔﻌﻴﺔ و ﺑﻌﺪ إزاﻟﺔ ﺣﺎﻟﺔ ﻋﺪم اﻟﺘﻌﻴﻴﻦ وﺟﺪﻧﺎ أن ،nﻭ exﻴﺅﻭل ﺇﻟﻰ.0 ) 1 .ln(xﻳﺆول إﻟﻰ.0ﻷﻭل ﻭﻫﻠﺔ ﻨﻬﺎﻴﺔ ﺍﻟﺠﺩﺍﺀ xn.exﻫﻲ ﺤﺎﻟﺔ ﻋﺩﻡ xn ﺘﻌﻴﻴﻥ. ﺣﻴﺚ اﻟﺠﺰء ⎜⎛ x → 1 ⎞⎟ ﻧﻬﺎﻳﺔ هﻮ 0 وﻭ ﺒﻌﺩ ﺇﺯﺍﻟﺔ ﺤﺎﻟﺔ ﻋﺩﻡ ﺍﻟﺘﻌﻴﻴﻥ ،ﻭﺠﺩﻨﺎ ﺃﻥ xn.ex ⎝ xn ⎠ ﻴﺅﻭل ﺇﻟﻰ .0 xnهﻨﺎ آﺬﻟﻚ ' xnﻳﺘﻔﻮق' ﻋﻠﻰ ).×× ln(x ﻭ 0ﻫﻭ ﻨﻬﺎﻴﺔ ). (xlex ﻫﻨﺎ ﻜﺫﻟﻙ ' exﻴﺘﻔﻭﻕ' ﻋﻠﻰ .×× xn ﺍﻟﻤﻼﺤﻅﺔ: ﺍﻟﻤﻼﺤﻅﺔ: ﺃﻤﺎﻡ ﺤﺎﻟﺔ ﻋﺩﻡ ﺘﻌﻴﻴﻥ :ﻋﻨﺩ ﺍﻟﻼﻨﻬﺎﻴﺔ ،ﺒﻌﻨﻰ ﺃﻤﺎﻡ ﺤﺎﻟﺔ ﻋﺩﻡ ﺘﻌﻴﻴﻥ :ﻋﻨﺩ ﺍﻟﻼﻨﻬﺎﻴﺔ ،ﺒﻤﻌﻨﻰ ﺍﻟﻘﻴﻤﺔ ﺍﻟﻤﻁﻠﻘﺔ ﻟﻭﺍﺤﺩ ﻤﻥ exﻭ xnﺘﺅﻭل ﺇﻟﻰ ﺍﻟﻘﻴﻤﺔ ﺍﻟﻤﻁﻠﻘﺔ ﻟﻭﺍﺤﺩ ﻤﻥ lnxﻭ xnﺘﺅﻭل ﺇﻟﻰ ∞.+ ∞.+ ' exﻴﺘﻔﻭﻕ' ﻋﻠﻰ xn ' xnﻴﺘﻔﻭﻕ' ﻋﻠﻰ )ln(x
ﺍﻟﻤﻼﺤﻅﺎﺕ ﺃﻋﻼﻩ ﺠﺩ ﻤﺜﻴﺭﺓ ﻟﻼﻫﺘﻤﺎﻡ ﻷﻨﻬﺎ ﺘﺠﻌﻠﻨﺎ ﻨﻜﺴﺏ\"ﺜﻘﺎﻓﺔ\" ﺘﻤﻜﻨﻨﺎ ﻤﻥ ﺍﻟﺘﺨﻤﻴﻥ. ﻤﺜﻼ:ﻟﻨﺤﺴﺏ ﺍﻟﻨﻬﺎﻴﺔ ) lim(x → x5 − e2x+3 ∞+ ﻷﻭل ﻭﻫﻠﺔ ،ﺤﺎﻟﺔ ﻋﺩﻡ ﺘﻌﻴﻴﻥ)ﻷﻥ ∞lim(x → x5 ) = + ∞+ ﻭ ∞( lim(x → −e2x+3 ) = − ∞+ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ\"ﺘﺘﻔﻭﻕ\" ﻋﻠﻰ ﻜل ﺩﺍﻟﺔ\"ﻗﻭﺓ\" ﺫﺍﺕ ﺍﻷﺱ ﺍﻟﻁﺒﻴﻌﻲ ﻏﻴﺭ ﺍﻟﻤﻌﺩﻭﻡ ﻭ ﻓﻲ ﻤﺜﺎﻟﻨﺎ ﻫﺫﺍ ،ﻨﻬﺎﻴﺔ ﺍﻟﺠﺯﺀ ﺤﻴﺙ ﺍﻷﺴﻴﺔ ﻫﻲ ∞.- ﺇﺫﻥ ﻨﺨﻤﻥ lim(x → x5 − e2x+3 ) = −∞ : ∞+ ﺍﻟﺒﺭﻫﺎﻥ: ex ﻭ ﻟﻨﺤﺎﻭل ﺇﺒﺭﺍﺯ ﻟﻨﻀﻊ f (x) = x5 − e2x+3 x2 ﻤﻥ ﺃﺠل xﻓﻲ *. ℜf (x) = x5 − ex.ex.e3 = x5 ⎛⎜1 − ex × ex × e3 ⎟⎞ ⎝ x5 ⎠ ﻟﻤﺎ ﻴﺅﻭل xﺇﻟﻰ ∞ x5 :+ﻴﺅﻭل ﺇﻟﻰ ∞+∞+ ﺇﻟﻰ exﻴﺅﻭل × e3 ∞+ﻭ ﺇﻟﻰ ﻴﺅﻭل ex x5)ﻷﻥ e3>0ﻭ exﻴﺅﻭل ﺇﻟﻰ ∞(+ ﺇﻟﻰ ∞- 1 −ﻴﺅﻭل ex × ex × e3 ﻤﻨﻪ x5 ﻭ ﻋﻠﻴﻪ ( )lim x → x5 − e2x+3 = −∞ : ∞+
ﺍﻟﻘﻭﻯ ﺫﺍﺕ ﺍﻷﺱ ﺍﻟﺤﻘﻴﻘﻲ ﻭ ﺍﻷﺴﺎﺱ ﺍﻟﻤﻭﺠﺏ ﺘﻤﺎﻤﺎﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﺎ ﻤﻭﺠﺒﺎ ﺘﻤﺎﻤﺎ ،ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺼﺤﻴﺢ ، nﻟﺩﻴﻨﺎ ln(an)=n.ln(a) :ﻤﻨﻪ ))an=exp(n.ln(a ﻤﻨﻪ ) an=enln(aﻭ ﺒﺎﻟﺘﻌﺭﻴﻑ ،ﺘﻤﺩﺩ ﻫﺫﻩ ﺍﻟﻜﺘﺎﺒﺔ. -ﺃ -ﺘﻌﺭﻴﻑ: ﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ ﻤﻭﺠﺒﺎ ﺘﻤﺎﻤﺎ. ﺒﺎﻟﺘﻌﺭﻴﻑ :ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ aα=eαln(a) :α -ﺏ-ﻗﻭﺍﻋﺩ ﺍﻟﺤﺴﺎﺏ: ﻤﺒﺭﻫﻨﺎﺕ:ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩﻴﻥ ﺤﻘﻴﻘﻴﻴﻥ ﻤﻭﺠﺒﻴﻥ ﺘﻤﺎﻤﺎ ﻭ bﻭ ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩﻴﻥ ﺤﻘﻴﻘﻴﻴﻥ αﻭ ،βﻟﺩﻴﻨﺎ : aα+β=aα×aβ(2 ln(aα)=αln(a)(1aα −β = aα (4 a −α = 1 (3 aβ aα(a.b)α=aα.bα(6 (aα)β=aα.β(5 ⎛⎜ a ⎟⎞α = aα (7 ⎠⎝b bαﺍﻟﺒﺭﻫﺎﻥ :ﺍﻟﺒﺭﻫﺎﻥ ﻋﻠﻰ ﺍﻟﻤﺴﺎﻭﻴﺎﺕ ﺍﻟﺴﺎﺒﻘﺔ ﻴﺘﻡ ﺒﺎﻻﻋﺘﻤﺎﺩ ﻋﻠﻰ ﺍﻟﺘﻌﺭﻴﻑ ) aα=eαlnaﻤﻥ ﺃﺠل *a∈ℜ+ ﻭ ( α∈ℜﻭ ﻋﻠﻰ ﺨﻭﺍﺹ ﺍﻟﺩﺍﻟﺘﻴﻥ ln ﻭ expﺴﻨﻜﺘﻔﻲ ﺒﺎﻟﺒﺭﻫﻨﺔ ﻋﻠﻰ ﺍﻟﺒﻌﺽ. ﻟﻴﻜﻥ aﻭ bﻋﻨﺼﺭﻴﻥ ﻤﻥ * ℜ+ﻭ ﻟﻴﻜﻥ αﻭ βﻋﺩﺩﻴﻥ ﻗﻴﻘﻴﻴﻥ. ) ln(aα)=ln(eαlnaﻭ ln(ex)=xﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ . x ﻭ ﻋﻠﻴﻪ ln(aα)=αlnaﻭ ﻫﻜﺫﺍ ﺘﻡ ﺍﻟﺒﺭﻫﺎﻥ ﻋﻠﻰ ﺍﻟﻤﺴﺎﻭﺍﺓ .(1 ) α βﻤﻥ ﺍﻟﺘﻌﺭﻴﻑ(( )a = e ) β ln(aα ) ﻤﻥ = e((1 ) β (α ln a = eαβ ln a
) = aαβﻤﻥ ﺍﻟﺘﻌﺭﻴﻑ( ﻭ ﻫﻜﺫﺍ ﺘﻡ ﺍﻟﺒﺭﻫﺎﻥ ﻋﻠﻰ ﺍﻟﻤﺴﺎﻭﺍﺓ (5 ) ) (ab)α = eα ln(abﻤﻥ ﺍﻟﺘﻌﺭﻴﻑ( ) ﻤﻥ ﺨﻭﺍﺹ (ln )= eαl (ln a+ln b = eα ln a+α ln b ) = eα ln a × eα lnbﻤﻥ ﺨﻭﺍﺹ (exp ) = aα × bαﻤﻥ ﺍﻟﺘﻌﺭﻴﻑ( ﻭ ﻫﻜﺫﺍ ﺘﻡ ﺍﻟﺒﺭﻫﺎﻥ ﻋﻠﻰ ﺍﻟﻤﺴﺎﻭﺍﺓ (6ﻤﻼﺤﻅﺔ:ﻟﻘﺩ ﻋﺭﻓﻨﺎ ﻨﻭﻋﺎ\"ﺠﺩﻴﺩ\" ﻤﻥ ﺍﻟﻘﻭﻯ ﻭ ﻫﻲ ﺍﻟﻘﻭﻯ ﺫﺍﺕ ﺍﻷﺴﺎﺱ ﻓﻲ * ℜ+ﻭ ﺍﻷﺱ ﻓﻲ ℜﻭ ﻨﻼﺤﻅﺃﻥ ﻫﺫﻩ ﺍﻟﻘﻭﻯ ﻟﻬﺎ ﻨﻔﺱ ﺍﻟﺨﻭﺍﺹ ﺍﻟﺤﺴﺎﺒﻴﺔ ﻤﻊ ﺍﻟﻘﻭﻯ ﺫﺍﺕ ﺍﻷﺱ ﺍﻟﺼﺤﻴﺢ.ﻤﺜﻼ:ﻟﻨﺤل ﻓﻲ ℜﺍﻟﻤﻌﺎﺩﻟﺔ (1).... 10x=7ﺤﻴﺙ xﻫﻭ ﺍﻟﻤﺠﻬﻭل. ﻤﻥ ﺍﺠل xﻓﻲ (1) ، ℜﺘﻜﺎﻓﺊ )ln(10x)=ln(7ﺘﻜﺎﻓﺊ )x.ln(10)=ln(7x = )ln(7 ﺘﻜﺎﻓﺊ )ln(10 ﺘﻜﺎﻓﺊ )x=log(7 ﻭ ﻋﻠﻴﻪ ﻤﺠﻤﻭﻋﺔ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ) (1ﻫﻲ }){log(7
ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﺫﺍﺕ ﺍﻷﺴﺎﺱ a -ﺤﻴﺙ aﻋﺩﺩ ﺤﻘﻴﻘﻲ ﺒﺤﻴﺙ a>0ﻭ a≠1 -ﺃ -ﺘﻌﺭﻴﻑ: ﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ ﺒﺤﻴﺙ a>0ﻭ a≠1 ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﺫﺍﺕ ﺍﻷﺴﺎﺱ aﻫﻲ ،ﺒﺎﻟﺘﻌﺭﻴﻑ ،ﺍﻟﺩﺍﻟﺔ ، xlax ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ .ℜ -ﺏ-ﺍﺘﺠﺎﻩ ﺘﻐﻴﺭ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﺫﺍﺕ ﺍﻷﺴﺎﺱ ﻭ ﺍﺴﺘﻨﺘﺎﺠﺎﺕ: ﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ ﻤﻭﺠﺒﺎ ﺘﻤﺎﻤﺎ ﻭ ﻴﺨﺘﻠﻑ ﻋﻥ .1 ﻟﻨﺴﻤﻲ expaﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﺫﺍﺕ ﺍﻷﺴﺎﺱ . ﺍﻟﺩﺍﻟﺔ expaﻤﻌﺭﻓﺔ ،ﻋﻠﻰ ،ℜﺒﺎﻟﺩﺴﺘﻭﺭ expa=ax ﺃﻱ ﺒﺎﻟﺩﺴﺘﻭﺭexpa(x)=exln(a) : ﺍﻟﺩﺍﻟﺔ ،uﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ،ℜﺒﺎﻟﺩﺴﺘﻭﺭu(x)=x.ln(a) :ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ،ℜﻭﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ u′ﻤﻌﺭﻓﺔ ﻋﻠﻰ ℜﺒﺎﻟﺩﺴﺘﻭﺭ ) u′(x)=ln(aﻤﻨﻪ expaﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ℜﻭ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ exp′a ﻤﻌﺭﻓﺔ ،ﻋﻠﻰ ℜﺒﺎﻟﺩﺴﺘﻭﺭ exp′a(x)=ln(a).exln(a) :ﺃﻱ ﺒﺎﻟﺩﺴﺘﻭﺭ exp′a(x)=ln(x) .ax ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ exln(a)>0 ،ℜﺃﻱ ax>0ﻤﻨﻪ ﺇﺸﺎﺭﺓ ) exp′a(xﻫﻲ ﺇﺸﺎﺭﺓ ).ln(a ﻤﺒﺭﻫﻨﺔ ﻭ ﺍﺴﺘﻨﺘﺎﺠﺎﺕ: ﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ ﻤﻭﺠﺒﺎ ﺘﻤﺎﻤﺎ ﺒﺤﻴﺙ .a≠1ﻓﻲ ﺍﻟﺤﺎﻟﺔ :0<a<1 ﻓﻲ ﺍﻟﺤﺎﻟﺔ :a>1ﻴﻜﻭﻥ ln(a)<0ﻤﻨﻪ ﻴﻜﻭﻥ ln(a)>0ﻤﻨﻪﺍﻟﺩﺍﻟﺔ xlax :ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ،ℜﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﺍﻟﺩﺍﻟﺔ xlax :ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ،ℜﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎﻋﻠﻰ .ℜ ﻋﻠﻰ .ℜﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩﻴﻥ ﺤﻘﻴﻘﻴﻴﻥ αﻭ ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩﻴﻥ ﺤﻘﻴﻘﻴﻴﻥ αﻭ .β .β β=αﻴﻜﺎﻓﺊ aβ=aα β=αﻴﻜﺎﻓﺊ aβ=aα β>αﻴﻜﺎﻓﺊ aβ<aα β>αﻴﻜﺎﻓﺊ aβ>aα β≥αﻴﻜﺎﻓﺊ aβ≤aα β≥αﻴﻜﺎﻓﺊ aβ≥aα
-ﺠـ -ﻨﻬﺎﻴﺎﺕ ﺍﻟﺩﺍﻟﺔ )،(xlaxﺤﻴﺙ a>0ﻭ ، a≠1ﻋﻨﺩ ∞ -ﻭ ﻋﻨﺩ ∞- ﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ ﻤﻭﺠﺒﺎ ﺘﻤﺎﻤﺎ ﺒﺤﻴﺙa≠1 : ﻤﻬﻤﺎ ﺘﻜﻭﻥ ﻗﻴﻤﺔ xﻓﻲ ax=exln(a):ℜ ﻓﻲ ﺍﻟﺤﺎﻟﺔ :0<a<1 ﻓﻲ ﺍﻟﺤﺎﻟﺔ :a>1 ln(a)<0 ln(a)>0ﻟﻤﺎ xﻴﺅﻭل ﺇﻟﻰ ∞ x.lna ،+ﻴﺅﻭل ﺇﻟﻰ ∞ -ﻤﻨﻪ ﻟﻤﺎ xﻴﺅﻭل ﺇﻟﻰ ∞ x.lna ،+ﻴﺅﻭل ﺇﻟﻰ ∞+ ex.lnaﻴﺅﻭل ﺇﻟﻰ .0 ﻤﻨﻪ ex.lnaﻴﺅﻭل ﺇﻟﻰ ∞.+ﻟﻤﺎ xﻴﺅﻭل ﺇﻟﻰ ∞ x.lna ،-ﻴﺅﻭل ﺇﻟﻰ ∞ -ﻤﻨﻪ ﻟﻤﺎ xﻴﺅﻭل ﺇﻟﻰ ∞ x.lna ،-ﻴﺅﻭل ﺇﻟﻰ ∞+ﻤﻨﻪ ex.lnaﻴﺅﻭل ﺇﻟﻰ ∞.+ ex.lnaﻴﺅﻭل ﺇﻟﻰ .0ﻤﻨﻪ lim(x → a x ) = 0 ﻤﻨﻪ ∞lim(x → a x ) = + ∞+ ∞+∞lim(x → ax ) = − lim(x → a x ) = 0 ∞− ∞− -ﺩ -ﺠﺩﻭل ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ ، xlaxﺤﻴﺙ aﻋﺩﺩ ﺤﻘﻴﻘﻲ ﺒﺤﻴﺙ a>0ﻭ a≠1ﻟﻴﻜﻥ aﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ ﺒﺤﻴﺙ a>0ﻭ a≠1ﻓﻲ ﻤﺎ ﻴﻠﻲ ،ﺠﺩﻭل ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ، xlax :ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ ،ℜ ﻭ ﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ:∞x - ﻓﻲ ﺍﻟﺤﺎﻟﺔ :a>1 ∞+ax ∞+ 0 ﺠﺩﻭل ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ xlax
y 3 )( γa 2 1 →j -4 -3 -2 -1 0 i→ 1 2 3 4 x -1 -2 -3 )(γaﺍﻟﻤﻨﺤﻨﻲ ﺍﻟﻤﻤﺜل ﻟﻠﺩﺍﻟﺔ xlaxﺒﺎﻟﻨﺴﺒﺔ ﺇﻟﻰ ﺍﻟﻤﻌﻠﻡ )(o;i; j ∞x - ﻓﻲ ﺍﻟﺤﺎﻟﺔ :1>a>0 ∞+ ∞ax + 0 ﺠﺩﻭل ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ xlax y 3 )( γ a 2 1 → j-4 -3 -2 -1 0 → 1 2 3 4x i -1 -2 -3 )(γaﺍﻟﻤﻨﺤﻨﻲ ﺍﻟﻤﻤﺜل ﻟﻠﺩﺍﻟﺔ xlaxﺒﺎﻟﻨﺴﺒﺔ ﺇﻟﻰ ﺍﻟﻤﻌﻠﻡ )(o;i; j ﻤﻼﺤﻅﺔ : ﻤﻥ ﺃﺠل xﻓﻲ exln(e)=ex ،ℜ ﻤﻨﻪ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ) ( expﻫﻲ ﺍﻟﺩﺍﻟﺔ ﺍﻷﺴﻴﺔ ﺫﺍﺕ ﺍﻷﺴﺎﺱ e
ﺘﻤﺎﺭﻴﻥ ﻭ ﻤﺸﻜﻼﺕ ﺤﻭل ﺍﻟﺩﻭﺍل ﺍﻷﺴﻴﺔ ﻭ ﺍﻟﺩﻭﺍل ﺍﻟﻠﻭﻏﺎﺭﻴﺘﻤﻴﺔ ﻤﻌﺎﺩﻻﺕ ،ﻤﺘﺭﺍﺠﺤﺎﺕ: ﺍﻟﺘﻤﺭﻴﻥ : 01 ﺤل ،ﻓﻲ ،ℜﻜل ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﻤﻌﺎﺩﻻﺕ ،ﺤﻴﺙ xﻫﻭ ﺍﻟﻤﺠﻬﻭل ،ﺍﻟﺘﺎﻟﻴﺔ:.. (ex − 5)(3ex − 2) = 0 ،(2)......... e5x+3 = e 2e−2x+1 ،(1)...... 3x−2 = 17 ،(4)........ 9 log(x) = −3 ،(3).... )،(5)... 5log8 (x =) = 2 log2 (x ،(6)... (log x)2 − ( 2 −1) log x = 2 (7).......... e2 × 3x × 32x × 33x = 5x × 52x × 53x × 54x ﺍﻟﺘﻤﺭﻴﻥ : 02 ﺤل ،ﻓﻲ ،ℜﻜل ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﻤﺘﺭﺍﺠﺤﺎﺕ ،ﺤﻴﺙ xﻫﻭﺍﻟﻤﺠﻬﻭل ،ﺍﻟﺘﺎﻟﻴﺔ : (4)..(lnx)2<2،(3)....e-2x+1>103،(2)....2-3e-x<0،(1)....2ex≥5 ،(7)...(0,5)x≤(0,5)3x+1،(6)...e2x-2ex+1≤0،(5)... (logx)2≥3 .(8)...7.3x>6x ﺍﻟﺘﻤﺭﻴﻥ : 03 ﺤل ،ﻓﻲ ،ℜﻜل ﻭﺍﺤﺩﺓ ﻤﻥ ﺍﻟﻤﻌﺎﺩﻻﺕ ،ﺤﻴﺙ xﻫﻭ ﺍﻟﻤﺠﻬﻭل ،ﺍﻟﺘﺎﻟﻴﺔ: x (3)....10e x − 31e 2 + 15 = 0 ،(2)...5ex+10e-x-51=0،(1)....3e2x-28ex+9=0 ﺍﻟﺘﻤﺭﻴﻥ : 04 -1ﺃﻨﺸﺭ ﻭ ﺒﺴﻁ ﻋﺒﺎﺭﺓ ﻜﺜﻴﺭ ﺍﻟﺤﺩﻭﺩ) ،P(xﻟﻠﻤﺘﻐﻴﺭ ﺍﻟﺤﻘﻴﻘﻲ ، xﺒﺤﻴﺙ )P(x)=(x+1)(3x-2)(2x-3 -2-ﻟﺘﻜﻥ fﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﻌﺭﻓﺔ ،ﻋﻠﻰ ،ℜﺒﺎﻟﺩﺴﺘﻭﺭ: f(x)=6e3x-7e2x-7ex+6 -ﺃ -ﺤل ،ﻓﻲ ،ℜﺍﻟﻤﻌﺎﺩﻟﺔ f (x)=0ﺤﻴﺙ xﻫﻭ ﺍﻟﻤﺠﻬﻭل. -ﺏ -ﺃﺩﺭﺱ ﺇﺸﺎﺭﺓ ) f (xﺘﺒﻌﺎ ﻟﻘﻴﻡ xﻓﻲ .ℜ ﺍﻟﺘﻤﺭﻴﻥ : 05
ﺤل ،ﻓﻲ ،ℜﺍﻟﻤﺘﺭﺍﺠﺤﺎﺕ ،ﺤﻴﺙ xﻫﻭ ﺍﻟﻤﺠﻬﻭل ،ﺍﻟﺘﺎﻟﻴﺔ: ،(2)....3.49x-4.7x+1+9<0،(1)....5e2x+10≥51ex(4)... e3x-4e2x-ex+4≤0،(3)..... 6(0,25)x-13(0,5)x+6>0 ﻤﺠﻤﻭﻋﺎﺕ ﺘﻌﺭﻴﻑ ﻭ ﻤﺸﺘﻘﺎﺕ : ﺍﻟﺘﻤﺭﻴﻥ : 06ﻋﻴﻥ ﺍﻟﻤﺠﻤﻭﻋﺔ Dﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ fﻭ ﺍﻟﺩﺍﻟﺔ ′ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ fﻓﻲ ﻜل ﺤﺎﻟﺔ ﻤﻥ ﺍﻟﺤﺎﻻﺕ ﺍﻟﺘﺎﻟﻴﺔ: f (1ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭf (x) = x2 + 2x − 2ex : f (2ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭf (x) = 1 + 3x2.ex : x f (x) = 3x + 5 f (3ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: ex f (4ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭf (x) = (0,5x2 + 2x).ex :f ( )x = 3e x +2 f (5ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: ex +3f )(x = 2− 5e x f (6ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: ex −1= )f (x 2x +3 f (7ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: 2ex − 4 f (8ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭf (x) = ex + x2 + 5 : f (9ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭf (x) = 3x2 + 5x −1 + e3x2+5x−1 : f (10ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭf (x) = (5e2x + 3ex + 1)10 : f (11ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭf (x) = (3x2 + 5x)(e2x − 3e−5x + 1) := )f (x x2 + 2x f (12ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: e2x − 4
f (x) = ln x + 3 x f (13ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: x+1 f (14ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭf (x) = x2 + e x−1 : ﺩﻭﺍل ﺃﺼﻠﻴﺔ ﻭ ﺘﻜﺎﻤﻼﺕ: ﺍﻟﺘﻤﺭﻴﻥ : 07ﻋﻴﻥ ﺍﻟﺩﻭﺍل ﺍﻷﺼﻠﻴﺔ ﻟﻠﺩﺍﻟﺔ fﻋﻠﻰ ﺍﻟﻤﺠﺎل Iﻓﻲ ﻜل ﺤﺎﻟﺔ ﻤﻥ ﺍﻟﺤﺎﻻﺕ ﺍﻟﺘﺎﻟﻴﺔ:[I=]-∞ ;0 ﻭ f )(x = ex + 1 + 5x +1 f (1ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: x2 f (2ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ f (x) = 2e0,5x + 7 x :ﻭ I=ℜ f (3ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ f (x) = 5xex2 + 3e5x :ﻭ I=ℜ f (4ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ f (x) = (x2 + 2)ex3+3x :ﻭ I=ℜ 1 [∞I=]0 ;+ ﻭ f )(x = e−x + ex f (5ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: x2 f (6ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ f (x) = (e2x + 3)(e3x + e−x −1) :ﻭ I=ℜI=ℜ ﻭ f )(x = 3e x + 5e2x +1 f 7ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: e6x I=ℜ ﻭ f )(x = ex f (8ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: 2ex +1[I=]-∞ ;0 ﻭ = )f (x x2 + e−x f (9ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: x3 − 3e−x f (10ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ f (x) = ex.(e2x + 2ex + 1)10 :ﻭ I=ℜ I=ℜ ﻭ f )(x = ex +1 f (11ﻤﻌﺭﻓﺔ ﺒﺎﻟﺩﺴﺘﻭﺭ: (ex + x)7
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