x2 + x - 4 → - 4 ﻷﻥ : x +1 →> 0 (2ﺘﺒﻴﺎﻥ ﺃﻨﻪ ﻴﻤﻜﻥ ﻜﺘﺎﺒﺔ f xﻋﻠﻰ ﺍﻟﺸﻜل ( ):)f (x = ax + b + c x +1 (ax + b) (x + )1 + c f ( )x = x+ 1 ﺇﺫﻥ :f )( x = ax 2 + a x + bx + b + c x +1f )( x = ax2 + (a + b) x + b + c x +1 a = 1 a = 1 b = 0 ﻭﻤﻨﻪ a + b = 1 :ﺃﻱ : c = -4 b + c = -4 )f (x =x - 4 ﺇﺫﻥ : x +1 -3ﺘﻌﻴﻴﻥ ﻤﻌﺎﺩﻻﺕ ﺍﻟﻤﺴﺘﻘﻴﻤﺎﺕ ﺍﻟﻤﻘﺎﺭﺒﺔ : ﺒﻤﺎ ﺃﻥ lim f ( x ) = -∞ :ﻭ ∞lim f ( x ) = + >< x →−1 x →−1 ﻓﺈﻥ x = -1 :ﻤﻌﺎﺩﻟﺔ ﻤﺴﺘﻘﻴﻡ ﻤﻘﺎﺭﺏ. lim -4 = 0 ﻭ f (x) = x - 4 ﻭ ﺒﻤﺎ ﺃﻥ : x→+∞ x + 1 x +1 ﻓﺈﻥ y = x :ﻤﻌﺎﺩﻟﺔ ﺍﻟﻤﺴﺘﻘﻴﻡ ﺍﻟﻤﻘﺎﺭﺏ ﺍﻟﻤﺎﺌل ﻋﻨﺩ ∞ +ﻭ ﻋﻨﺩ ∞. − -4ﺩﺭﺍﺴﺔ ﺍﻟﻭﻀﻊ ﺍﻟﻨﺴﺒﻲ ﻟـ ∆ ﻭ )( ): (C
f ( x) -y= -4 x +1 : ﻭﻤﻨﻪ x −∞ -1 +∞ x+1 - + + - f (x)− y ( ). (C) ﺇﺫﻥ ∆ ﻻ ﻴﻘﻁﻊ ( ∆ ) ( ﻴﻘﻊ ﻓﻭﻕC) : x ∈ ]-∞ ; -1[ ﻟﻤﺎ ( ∆ ) ( ﻴﻘﻊ ﺘﺤﺕC) : x ∈ ]1 ; +∞[ ﻟﻤﺎ . 8ﺍﻟﺘﻤﺭﻴﻥ : ﺤﺴﺎﺏ ﺍﻟﻨﻬﺎﻴﺎﺕDf = ]-∞ ; +∞[( )lim f x = lim 2x + x2 + 1 = lim 2x+ x2 1 + 1 x→−∞ x→−∞ x→−∞ x2 = lim 2x + x2 1+ 1 x→−∞ x2 = lim 2x + x . 1+ 1 x→−∞ x2 = lim 2x - x 1+ 1 = lim x 2 - 1+ 1 = -∞ x→−∞ x2 x2 x→−∞ lim f ( x) = lim 2x + x2 + 1 = +∞x → +∞ x→+∞ : ﺤﺴﺎﺏ-2lim f ( x ) - 3x = lim 2x + x2 + 1 - 3xx→+∞ x→+∞
= lim -x + x2 + 1 )x2 + 1 ∞x→+ ( ) (-x + x2 + 1 -x - = lim x→+∞ - x - x2 + 1 )= lim x2 - (x2 + 1 x→+∞ - x - x2 + 1 = lim −1 = 0 x→+∞ − x - x2 + 1lim f ( x ) - x = lim 2x + x2 + 1 - x∞x → − ∞x→− = lim x + x2 + 1 ∞x→− ( ) ( )x + x2 + 1 x - x2 + 1 = lim x→−∞ x - x2 + 1 = lim −1 = 0 x→−∞ − x - x2 + 1 -3ﺘﻌﻴﻴﻥ ﻤﻌﺎﺩﻻﺕ ﺍﻟﻤﺴﺘﻘﻴﻤﺎﺕ ﺍﻟﻤﻘﺎﺭﺒﺔ : lim f ( x) - 3x =0 ﺒﻤﺎ ﺃﻥ : ∞x → + ﻓﺈﻥ y = 3x :ﻤﻌﺎﺩﻟﺔ ﻤﺴﺘﻘﻴﻡ ﻤﻘﺎﺭﺏ ﻤﺎﺌل ﻋﻨﺩ ∞. + ( )lim f x ﺒﻤﺎ ﺃﻥ - x = 0 : ∞x→− ﻓﺈﻥ y = x :ﻤﻌﺎﺩﻟﺔ ﻤﺴﺘﻘﻴﻡ ﻤﻘﺎﺭﺏ ﻤﺎﺌل ﻋﻨﺩ ∞. − ﺍﻟﺘﻤﺭﻴﻥ. 9 -1ﺘﻌﻴﻴﻥ aﻭ : b ﻟﺩﻴﻨﺎ -1 ≤ sin x ≤ 1 :ﻭﻤﻨﻪ 3 ≤ 4 + sin x ≤ 5 : -2ﺘﺒﻴﺎﻥ ﺃﻥ v( x ) ≤ f ( x ) ≤ u( x ) :
3 ≤ 4 + sin x ≤ 5 : ﻟﺩﻴﻨﺎ 3 ≤ 4 + sin x ≤ 5 : ﻭﻋﻠﻴﻪ x2 x2 x2 3 5 x2 ≤ f (x) ≤ x2 : ﻭﻤﻨﻪ : ﺍﺴﺘﻨﺘﺎﺝ ﺍﻟﻨﻬﺎﻴﺎﺕ-3 lim 3 = lim 5 =0 : ﺒﻤﺎ ﺃﻥx x2 x→+∞ x2 x → +∞ lim f ( x) = 0 : ﻓﺈﻥ x→+∞ lim 3 = lim 5 =0 : ﺒﻤﺎ ﺃﻥx x2 x→−∞ x2 x → −∞ lim f ( x) = 0 : ﻓﺈﻥ x→−∞ lim f ( x) = lim 4 + sin x = +∞ -4 x→0 x→0 x2 . 10ﺍﻟﺘﻤﺭﻴﻥ : ﺤﺴﺎﺏ ﺍﻟﻨﻬﺎﻴﺎﺕ lim f ( x) ; lim f ( x) x → −∞ x→+∞ f ( x) = - 1 : α=1 ﺃﻱ α - 1 = 0 ﺇﺫﺍ ﻜﺎﻥx 3 1 ( ) ( )lim f 3 x→+∞ x = lim f x = - : ﻭﻋﻠﻴﻪ x → +∞ α + 1= 0 ﺃﻱα - 1 ≠ 0 ﻭ α2 - 1 = 0 : ﺇﺫﺍ ﻜﺎﻥx . α = -1 : ﻭﻤﻨﻪf ( x) = -2x + 1 = 2 x - 1 -3 3 3
( )lim fx = lim 2 x = ∞- ∞x → − 3∞x → −( )lim fx = lim 2 x = ∞+ ∞x → + 3∞x → + xﺇﺫﺍ ﻜﺎﻥ }α ∈ - {-1 ; 1 (α - 1) x = α - 1 = 1 α2 - 1 x α2 - 1 α + 1( )lim f ( x) = lim∞x→− ∞x→− )(α - 1 x α-1 1 x α2 - 1 α+1 α2 - 1( )lim f ( x) = lim = =∞x→+ ∞x→+ ﺍﻟﺘﻤﺭﻴﻥ. 11 -1ﺘﻌﻴﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺍﻟﺘﻌﺭﻴﻑ : } Df = - {1ﺃﻱ Df = ]-∞ ; 1[ ∪ ]1 ; +∞[ : -2ﺩﺭﺍﺴﺔ ﺍﻻﺴﺘﻤﺭﺍﺭﻴﺔ ﻋﻨﺩ : -1lim f ( x) = lim x3 + 1 = lim (x + 1) (x2 - x + )1 = 3 x +1 x+ 1x→−1 x→−1 x→−1 ﻭﻤﻨﻪ fﻤﺴﺘﻤﺭﺓ ﻋﻨﺩ ( ) ( ). -1 lim f x =f −1 ﻭﻋﻠﻴﻪ : x→−1 ﺍﻟﺘﻤﺭﻴﻥ. 12 -ﺩﺭﺍﺴﺔ ﺍﻻﺴﺘﻤﺭﺍﺭﻴﺔ ﻋﻠﻰ ﻟﻠﺩﺍﻟﺔ : f xﻤﻥ ﺃﺠل ∞ : x ∈ 1 ; +ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻷﻨﻬﺎ ﺩﺍﻟﺔ ﻨﺎﻁﻘﺔ ] [. xﻤﻥ ﺃﺠل : x ∈ -∞ ; 1ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻷﻨﻬﺎ ﺩﺍﻟﺔ ﻜﺜﻴﺭﺓ ﺤﺩﻭﺩ ] [. f )(1 = 1 ﻭﻤﻨﻪ : )f (1 = (1)2 x 2 (1)2 + 1
( )lim f x = lim x2 = 12 >x + 1 2x→1 > x→1( )lim f x = lim −1 + 1 = 02 < <xx→1 x→1 ﺇﺫﻥ fﻏﻴﺭ ﻤﺴﺘﻤﺭﺓ ﻋﻨﺩ 1ﻷﻨﻬﺎ ﻻ ﺘﻘﺒل ﻨﻬﺎﻴﺔ ﻋﻨﺩ .1 ﺍﻟﺘﻤﺭﻴﻥ. 13 ﺘﻌﻴﻴﻥ bﺒﺤﻴﺙ ﺘﻜﻭﻥ fﻤﺴﺘﻤﺭﺓ ﻋﻨﺩ : 0 ﻟﺩﻴﻨﺎ f (0) = 2(0)2 + 1 :ﻭﻤﻨﻪ f (0) = 1 :( )lim f x = lim ax + b = b2 >x + 4 4x→0 > x→0lim f ( x) = lim 2x2 + 1 = 1<<x→0 x→0 ﺤﺘﻰ ﺘﻜﻭﻥ fﻤﺴﺘﻤﺭﺓ ﻋﻨﺩ 0ﻴﺠﺏ ﺃﻥ ﻴﻜﻭﻥ : ﻭﻤﻨﻪ b = 4 b =1 4 ﺍﻟﺘﻤﺭﻴﻥ. 14 ﺘﻌﻴﻴﻥ ﻋﺩﺩ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ ( )f x = 0 : (1ﻓﻲ ﺍﻟﻤﺠﺎل -∞ ; -3 :ﻟﺩﻴﻨﺎ f :ﻤﺴﺘﻤﺭﺓ ﻭ ﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ] ] ∞lim f ( x) = - ﻭ ﻭ ﻟﺩﻴﻨﺎ f ( −3) = 1 : ∞x→− ﻭﻤﻨﻪ ﻟﻠﻤﻌﺎﺩﻟﺔ f x = 0ﺤل ﻭﺤﻴﺩ ﻓﻲ ﺍﻟﻤﺠﺎل ] [ ( ). -∞ ; -3 (2ﻓﻲ ﺍﻟﻤﺠﺎل : -3 ; -2ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻭ ﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ] [ ﻭﻟﺩﻴﻨﺎ f −3 = 1ﻭ f −2 = -3ﻭﻤﻨﻪ ﺤﺴﺏ ﻨﻅﺭﻴﺔ ﺍﻟﻘﻴﻡ) ( ) ( ﺍﻟﻤﺘﻭﺴﻁﺔ ﻟﻠﻤﻌﺎﺩﻟﺔ f x = 0ﺤل ﻭﺤﻴﺩ ﻓﻲ ﺍﻟﻤﺠﺎل ] [ ( ). -3 ; -2 (3ﻓﻲ ﺍﻟﻤﺠﺎل : -2 ; 3ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻭ ﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ] [
ﻭﻟﺩﻴﻨﺎ f −2 = -3 :ﻭ f 3 = 4ﻭﻤﻨﻪ ﺤﺴﺏ ﻨﻅﺭﻴﺔ ﺍﻟﻘﻴﻡ) ( ) ( ﺍﻟﻤﺘﻭﺴﻁﺔ ﻟﻠﻤﻌﺎﺩﻟﺔ f x = 0ﺤل ﻭﺤﻴﺩ ﻓﻲ ﺍﻟﻤﺠﺎل ] [ ( ). -2 ; 3 ﻭﺒﺎﻟﺘﺎﻟﻲ :ﻋﺩﺩ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ f x = 0ﻋﻠﻰ ﻫﻲ ﺜﻼﺙ ﺤﻠﻭل( ). ﺍﻟﺘﻤﺭﻴﻥ. 15 = Df (1ﻤﺠﻤﻭﻋﺔ ﺍﻟﺘﻌﺭﻴﻑ : (2ﺩﺭﺍﺴﺔ ﺍﻻﺴﺘﻤﺭﺍﺭﻴﺔ ﻋﻠﻰ : D f f ( )x = x + x -1 ;x >1 ﻟﺩﻴﻨﺎ : f ( )x = x - x -1 ;x <1 x -1 x -1 f (1) = 2 f (x) = x + 1 ; x > 1 f ( )x = x - 1 ; x < 1 ﻭﻤﻨﻪ : f )(1 = 2 xﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ ﺍﻟﻤﺠﺎل ∞ 1 ; +ﻷﻨﻬﺎ ﺩﺍﻟﺔ ﻜﺜﻴﺭﺓ ﺍﻟﺤﺩﻭﺩ[ ] xﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ -∞ ; 1ﻷﻨﻬﺎ ﺩﺍﻟﺔ ﻜﺜﻴﺭﺓ ﺤﺩﻭﺩ ] [. lim f ( x) = lim (x - 1) = 0 x << x→1 x→1lim f ( x) = lim x + 1 = 2>>x→1 x→1 ﻭﻤﻨﻪ fﻏﻴﺭ ﻤﺴﺘﻤﺭﺓ ﻋﻨﺩ 1ﻭﺒﺎﻟﺘﺎﻟﻲ fﻏﻴﺭ ﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ . D f ﺍﻟﺘﻤﺭﻴﻥ. 16 ﺘﻌﻴﻴﻥ ﻋﺩﺩ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ ( )f x = 2
(1ﻓﻲ ﺍﻟﻤﺠﺎل : -∞ ; 0ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻭ ﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻭ ﺘﺄﺨﺫ] ] ﻗﻴﻤﻬﺎ ﻓﻲ ﺍﻟﻤﺠﺎل -4 ; 4ﻭ ﺒﻤﺎ ﺃﻥ 2 ∈ -4 ; 4ﻓﺈﻥ ﻟﻠﻤﻌﺎﺩﻟﺔ] ] ] ] f x = 2ﺤل ﻭﺤﻴﺩ ﺤﺴﺏ ﻨﻅﺭﻴﺔ ﺍﻟﻘﻴﻡ ﺍﻟﻤﺘﻭﺴﻁﺔ ( ). (2ﻓﻲ ﺍﻟﻤﺠﺎل ∞ : 0 ; +ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻭ ﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ ﻭ ﺘﺄﺨﺫ[ [ﻗﻴﻤﻬﺎ ﻓﻲ ﺍﻟﻤﺠﺎل -2 ; 4ﻭ ﺒﻤﺎ ﺃﻥ 2 ∈ -2 ; 4ﻓﺈﻥ ﻟﻠﻤﻌﺎﺩﻟﺔ f x = 2ﺤل] [ [ ] ) ( ﻭﺤﻴﺩ ﺤﺴﺏ ﻨﻅﺭﻴﺔ ﺍﻟﻘﻴﻡ ﺍﻟﻤﺘﻭﺴﻁﺔ. ﺇﺫﻥ ﻟﻠﻤﻌﺎﺩﻟﺔ f x = 2ﺤﻠﻴﻥ ﻓﻲ ( ). ﺍﻟﺘﻤﺭﻴﻥ. 17 ﺇﻨﺸﺎﺀ ﺒﻴﺎﻥ ﺍﻟﺩﺍﻟﺔ fﺒﺂﻟﺔ ﺒﻴﺎﻨﻴﺔ ﺍﻟﻤﻌﺎﺩﻟﺔ f ( x) 0ﺘﻘﺒل ﺤﻼ ﻭﺤﻴﺩﺍ ﻤﺤﺼﻭﺭ ﻓﻲ @ >. 1,78 ; 1,79 ﺍﻟﺘﻤﺭﻴﻥ. 18
; 0 π 2x - cosx = 0 ﺇﺜﺒﺎﺕ ﺃﻥ ﺍﻟﻤﻌﺎﺩﻟﺔ : ﺘﻘﺒل ﻋﻠﻰ ﺍﻷﻗل ﺤﻼ ﻓﻲ ﺍﻟﻤﺠﺎل 6 xﺍﻟﺩﺍﻟﺔ fﻫﻲ ﻤﺠﻤﻭﻉ ﺩﺍﻟﺘﻴﻥ ﻭ ﻤﻨﻪ ﻓﻬﻲ ﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ ﻷﻥ ﺍﻟﺩﺍﻟﺘﻴﻥ ﻤﺴﺘﻤﺭﺘﻴﻥ ﻋﻠﻰ . f π = π - 3 ﻭ ﻋﻠﻴﻪ : f π = 2π - cos π x 6 3 2 6 6 6 f π > 0 ﻭﻋﻠﻴﻪ : f π = 2π -3 3 ﺇﺫﻥ : 6 6 6 f (0) = 2(0) - cos0 xﻭﻋﻠﻴﻪ f (0) = -1 : f π , f )(0 <0 ﺇﺫﻥ : 6 πﺤل ﻋﻠﻰ ﺍﻷﻗل ﻓﻲ ﺍﻟﻤﺠﺎل 6 ; ( )0 f x ﻭﺤﺴﺏ ﻨﻅﺭﻴﺔ ﺍﻟﻘﻴﻡ ﺍﻟﻤﺘﻭﺴﻁﺔ ﻟﻠﻤﻌﺎﺩﻟﺔ = 0 . ﺍﻟﺘﻤﺭﻴﻥ. 19 -1ﺩﺭﺍﺴﺔ ﺍﻻﺴﺘﻤﺭﺍﺭﻴﺔ ﻋﻨﺩ : 0)lim f ( x x sin x 2x sin x cos x 1 - cosx 2 2 x→0 = lim = lim x 2 x→0 x→0 1 - 1 - 2sin2 2x sin x cos x x cos x 2 2 = lim 2= lim x x→0 x x→0 2 sin 2 2 sin 2
cos x cos x 2 2= lim x = lim x x→0 sin 2 x→0 sin 2 x 2. x 2 2 cos x 2= lim x =2 x→0 2 sin x 2 ( ) ( ). 0 f =f ﻭﻋﻠﻴﻪ fﻤﺴﺘﻤﺭﺓ ﻋﻨﺩ lim x 0 ﺇﺫﻥ x→0 -2ﺩﺭﺍﺴﺔ ﺍﻻﺴﺘﻤﺭﺍﺭﻴﺔ ﻋﻠﻰ : D f f )( x = x sin x : ﻟﺩﻴﻨﺎ 1 - cosx xﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ ﻷﻨﻬﺎ ﺠﺩﺍﺀ ﺩﺍﻟﺘﻴﻥ ﻤﺴﺘﻤﺭﺘﻴﻥ ﻋﻠﻰ . ﻭﻟﺩﻴﻨﺎx sin x : xﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ ﻷﻨﻬﺎ ﻤﺠﻤﻭﻉ ﺩﺍﻟﺘﻴﻥ ﻤﺴﺘﻤﺭﺘﻴﻥ ﻋﻠﻰ . ﻭﻟﺩﻴﻨﺎ 1 - cosx :ﺇﺫﻥ ﺍﻟﺩﺍﻟﺔ fﻫﻲ ﺤﺎﺼل ﻗﺴﻤﺔ ﺩﺍﻟﺘﻴﻥ ﻤﺴﺘﻤﺭﺘﻴﻥ ﻋﻠﻰ ﻓﻬﻲ ﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ . ﻭﻤﻨﻪ ﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ Df - π ; 0 ∪ 0 ; π 2 2 ﺍﻟﺘﻤﺭﻴﻥ. 20 -1ﺍﻟﺒﺭﻫﺎﻥ ﻋﻠﻰ ﻭﺠﻭﺩ : αﻨﻌﺭﻑ ﺍﻟﺩﺍﻟﺔ gﻜﻤﺎﻴﻠﻲ g x = f x - x :ﻋﻠﻰ ﺍﻟﻤﺠﺎل [ ] ( ) ( )0 ; 1 xﺍﻟﺩﺍل gﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ 0 ; 1ﻷﻨﻬﺎ ﻤﺠﻤﻭﻉ ﺩﺍﻟﺘﺎﻥ ﻤﺴﺘﻤﺭﺘﺎﻥ ﻋﻠﻰ [ ] [ ]. 0 ; 1 xﻭﻟﺩﻴﻨﺎ ) g (0) = f (0ﻭ g (1) = f (1) - 1
ﺒﻤﺎ ﺃﻥ f xﺘﻨﺘﻤﻲ ﺇﻟﻰ ﺍﻟﻤﺠﺎل 0 ; 1ﻓﺈﻥ [ ]( ) ( )0 ≤ f x ≤ 1 : ﺃﻱ ﺃﻥ 0 ≤ f (0) ≤ 1 :ﻭ ﻋﻠﻴﻪ 0 ≤ g (0) ≤ 1 ﺇﺫﻥ . g (0) ≥ 0 ﻭﻜﺫﺍﻟﻙ 0 ≤ f (1) ≤ 1ﻭﻋﻠﻴﻪ -1 ≤ f (1) - 1 ≤ 0 ﺇﺫﻥ g (1) ≤ 0ﻭﻤﻨﻪ g (0) . g(1) ≤ 0 : ﻭﺤﺴﺏ ﻨﻅﺭﻴﺔ ﺍﻟﻘﻴﻡ ﺍﻟﻤﺘﻭﺴﻁﺔ ﻴﻭﺠﺩ ﻋﻠﻰ ﺍﻷﻗل ﻋﺩﺩ αﻤﻥ ﺍﻟﻤﺠﺎل 0 ; 1ﺒﺤﻴﺙ] [ g(α) = 0 ﺃﻱ f (α) - α = 0ﻭ ﻋﻠﻴﻪ f (α) = α : -2ﺍﻟﺘﻔﺴﻴﺭ ﺍﻟﻬﻨﺩﺴﻲ ﻟﻠﻨﺘﻴﺠﺔ :ﺍﻟﻌﺩﺩ αﻫﻭ ﺤل ﻟﻠﻤﻌﺎﺩﻟﺔ f x = xﻭﻤﻨﻪ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ ﻟﻠﺩﺍﻟﺔ fﻴﺘﻘﺎﻁﻊ ﻤﻊ) ( ﺍﻟﻤﻨﺼﻑ ﺍﻷﻭل y = x :ﻓﻲ ﻨﻘﻁﺔ ﻓﺎﺼﻠﺘﻬﺎ . α -3ﻟﻨﺩﺭﺱ ﺼﺤﺔ ﺍﻟﻨﺘﺎﺌﺞ ﺍﻟﺴﺎﺒﻘﺔ ﻓﻲ ﺍﻟﻤﺠﺎل [ ]. a ; b ﻟﺘﻜﻥ ﺍﻟﺩﺍﻟﺔ gﺤﻴﺙ . g ( x ) = f ( x ) - x : xﺍﻟﺩﺍﻟﺔ gﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ a ; bﻷﻨﻬﺎ ﻤﺠﻤﻭﻉ ﺩﺍﻟﺘﺎﻥ ﻤﺴﺘﻤﺭﺘﺎﻥ ﻋﻠﻰ [ ] [ ]a ; b g(a) = f (a) - a xﻭ g(b) = f (b) - b ﻟﺩﻴﻨﺎ a ≤ f ( x ) ≤ b :ﻭﻋﻠﻴﻪ a ≤ f (a ) ≤ b : ﻭﻤﻨﻪ 0 ≤ f (a ) - a ≤ b-a :ﻭﺒﺎﻟﺘﺎﻟﻲ f (a) - a ≥ 0 : ﺃﻱ ﺃﻥ g (a) ≥ 0 : ﻭﻜﺫﻟﻙ a ≤ f (b) ≤ b :ﻭﻋﻠﻴﻪ g (b) ≤ 0 : ﺇﺫﻥ g(a) . g(b) ≤ 0 : ﻭﻤﻨﻪ ﺤﺴﺏ ﻨﻅﺭﻴﺔ ﺍﻟﻘﻴﻡ ﺍﻟﻤﺘﻭﺴﻁﺔ ﻴﻭﺠﺩ ﻋﻠﻰ ﺍﻷﻗل ﻋﺩﺩ αﻤﻥ ﺍﻟﻤﺠﺎل [ ]a ; b ﺒﺤﻴﺙ f (α) - α = 0ﻭﻋﻠﻴﻪ f (α) = α
ﻭﻋﻠﻴﻪ C fﻴﺘﻘﺎﻁﻊ ﻤﻊ ﺍﻟﻤﻨﺼﻑ ﺍﻷﻭل ﻓﻲ ﻨﻘﻁﺔ ﻓﺎﺼﻠﺘﻬﺎ ( ). α ﺇﺫﻥ ﺘﺒﻘﻰ ﺍﻟﻨﺘﺎﺌﺞ ﺍﻟﺴﺎﺒﻘﺔ ﺼﺤﻴﺤﺔ ﺍﻟﺘﻤﺭﻴﻥ. 21 (1ﺤل ﺍﻟﻤﻌﺎﺩﻟﺔ x2 - 13x + 36 = 0 : ∆ =25ﻭ ﻤﻨﻪ ﻟﻠﻤﻌﺎﺩﻟﺔ ﺤﻠﻴﻥ : x2 = 13 + 5 = 9 ﻭ x1 = 13 - 5 = 4 2 2 (2ﺤل ﺍﻟﻤﻌﺎﺩﻟﺔ x6 - 13x3 + 36 = 0 : ﺒﻭﻀﻊ x3 = zﻨﺠﺩ z2 - 13z + 36 = 0 : ﺍﻟﺤﻠﻴﻥ z1 = 4و z2 = 9ﻭﻤﻨﻪ x3 = 4 :ﻭ x3 = 9 ﻭﻋﻠﻴﻪ x = 3 4 :ﺃﻭ x = 3 9 (3ﺤل ﺍﻟﻤﻌﺎﺩﻟﺔ x2n - 13xn + 36 = 0 : ﺒﻭﻀﻊ xn = yﻨﺠﺩ y2 - 13y + 36 = 0 : ﺍﻟﺤﻠﻴﻥ y1 = 4 :ﻭ y2 = 9 ﻭﻋﻠﻴﻪ xn = 4 :ﺃﻭ xn = 9 ﻭﻤﻨﻪ x = n 4 :ﺃﻭ x = n 9 ﺍﻟﺘﻤﺭﻴﻥ. 22 ﻨﻌﺘﺒﺭ ﺩﺍﻟﺔ ﻜﺜﻴﺭﺓ ﺤﺩﻭﺩ ﻤﻥ ﺍﻟﺩﺭﺠﺔ nﻭﺩﺭﺠﺘﻪ ﻓﺭﺩﻴﺔ( )fx = an xn + a xn +. . . + a1 x + a0 n-1 ﺤﻴﺙ an ≠ 0ﻭ nﻋﺩﺩ ﻓﺭﺩﻱ ﻨﻔﺭﺽ an > 0 xﺍﻟﺩﺍﻟﺔ fﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ . ﻭ) ( x lim an xn lim f = ∞= + ∞x→+ ∞x → + ( )lim f x = lim an xn ∞= - ∞x→− ∞x→−
.ﺃﻱ ﺃﻥ ﻭﻋﻠﻴﻪ ﺤﺴﺏ ﻨﻅﺭﻴﺔ ﺍﻟﻘﻴﻡ ﺍﻟﻤﺘﻭﺴﻁﺔ ﻟﻠﻤﻌﺎﺩﻟﺔ f x = 0ﺤل ﻋﻠﻰ ﺍﻷﻗل ﻓﻲ) ( f xﻴﻨﻌﺩﻡ ﻤﺭﺓ ﻭﺍﺤﺩﺓ ﻋﻠﻰ ﺍﻷﻗل( ).
ﺍﻻﺸﺘﻘﺎﻗﻴﺔ ﺍﻟﻜﻔﺎﺀﺓ ﺍﻟﻤﺴﺘﻬﺩﻓﺔ -1ﺘﻭﻅﻴﻑ ﺍﻟﻤﺸﺘﻘﺎﺕ ﻟﺤل ﻤﺸﻜﻼﺕ. - 2ﺍﺴﺘﻌﻤﺎل ﺍﻟﻤﺸﺘﻘﺎﺕ ﻟﺩﺭﺍﺴﺔ ﺘﻐﻴﺭﺍﺕ ﺩﺍﻟﺔ . -3ﺍﺴﺘﻌﻤﺎل ﺍﻟﻤﺸﺘﻘﺎﺕ ﻟﺘﻌﻴﻴﻥ ﺍﻟﺘﻘﺭﻴﺏ ﺍﻟﺨﻁﻲ ﻟﺩﺍﻟﺔ -4ﺍﺴﺘﻌﻤﺎل ﺍﻟﻤﺸﺘﻘﺎﺕ ﻟﺘﻌﻴﻴﻥ ﻨﻘﻁ ﺍﻻﻨﻌﻁﺎﻑ ﻭﺍﻟﻨﻘﻁﺔ ﺍﻟﺯﺍﻭﻴﺔ. -5ﺤﺴﺎﺏ ﻤﺸﺘﻕ ﺩﺍﻟﺔ ﻤﺭﻜﺒﺔ. -6ﺤل ﻤﻌﺎﺩﻻﺕ ﺘﻔﺎﻀﻠﻴﺔ y′ = f ( x ) :ﻭ ) y′′ = f ( xﺘﺼﻤﻴﻡ ﺍﻟﺩﺭﺱ ﺃﻨﺸﻁﺔﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ ﻋﻨﺩ ﻋﺩﺩ ﻨﻘﻁﺔ ﺍﻻﻨﻌﻁﺎﻑ ﺍﻟﻤﻌﺎﺩﻻﺕ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ ﺘﻜﻨﻭﻟﻭﺠﻴﺎ ﺍﻹﻋﻼﻡ ﻭ ﺍﻻﺘﺼﺎل ﺘﻤـﺎﺭﻴﻥ ﻭ ﻤﺸﻜﻼﺕ ﺍﻟﺤـﻠــــــﻭل
ﺃﻨﺸﻁﺔ ﺍﻟﻨﺸﺎﻁ : 1 -1ﺃﻨﺸﺊ ﺒﺂﻟﺔ ﺒﻴﺎﻨﻴﺔ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ ) (Cﻟﻠﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ \ﻭﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ ﻟﻠﻤﺴﺘﻘﻴﻡ) ( f x = 2x ﻜﻤﺎ ﻴﻠﻲ x2 + 1 : ∆ ﺍﻟﺫﻱ ﻤﻌﺎﺩﻟﺘﻪ ( ). y = 2x : -2ﺍﺩﺭﺱ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ ﺍﻟﻌﺩﺩ . 0ﻤﺎﺫﺍ ﺘﺴﺘﻨﺘﺞ ؟ -3ﻨﺎﻗﺵ ﺒﻴﺎﻨﻴﺎ ﻭﻀﻌﻴﺔ ﺍﻟﺒﻴﺎﻥ ) (Cﺒﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﺴﺘﻘﻴﻡ ∆ ﺘﺄﻜﺩ ﻤﻥ) ( ﺼﺤﺔ ﺍﻟﻨﺘﺎﺌﺞ ﺤﺴﺎﺒﻴﺎ .ﻤﺎﺫﺍ ﺘﺴﺘﻨﺘﺞ ؟ ﺍﻟﺤل : -1ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ y1,510,5-2,5 -2 -1,5 -1 -0,5 0 0,5 1 1,5 2 2,5 x -0,5-1 -2ﺩﺭﺍﺴﺔ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ ﺍﻟﻌﺩﺩ : 0 ﻟﺩﻴﻨﺎ Df = \ :
f )(0 +h -f )(0 2hlim h = lim h2 + 1 hh→0 x→0 = lim 2h × 1 = lim 2 =2 h→0 h2 + 1 h h→0 h2 + 1 ﻭﻋﻠﻴﻪ ﺍﻟﺩﺍﻟﺔ fﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ ﺍﻟﻌﺩﺩ 0ﻟﺩﻴﻨﺎ ( )f ′ 0 = 2ﺍﻻﺴﺘﻨﺘﺎﺝ :ﺍﻟﻤﺴﺘﻘﻴﻡ ∆ ﻴﺸﻤل ﺍﻟﻤﺒﺩﺃ 0ﻭ ﻤﻌﺎﻤل ﺘﻭﺠﻴﻬﻪ 2ﻭ ﻋﻠﻴﻪ ∆ ﻫﻭ ﺍﻟﻤﻤﺎﺱ) ( ) ( ﻟﻠﻤﻨﺤﻨﻲ ) (Cﻓﻲ ﺍﻟﻤﺒﺩﺃ . 0 -3ﻭﻀﻌﻴﺔ ﺍﻟﺒﻴﺎﻥ ) (Cﻭ ﺍﻟﻤﺴﺘﻘﻴﻡ ∆ ﺒﻴﺎﻨﻴﺎ ( ). ﻓﻲ ﺍﻟﻤﺠﺎل : -∞ ; 0ﺍﻟﺒﻴﺎﻥ ) (Cﻴﻘﻊ ﻓﻭﻕ ∆[ ] ) ( ﻓﻲ ﺍﻟﻤﺠﺎل ∞ : 0 ; +ﺍﻟﺒﻴﺎﻥ ) (Cﻴﻘﻊ ﺘﺤﺕ ∆[ ] ) ( ﻓﻲ ﺍﻟﻨﻘﻁﺔ Oﺍﻟﺒﻴﺎﻥ ) (Cﻭ ∆ ﻴﺘﻘﺎﻁﻌﺎﻥ( ). -ﺩﺭﺍﺴﺔ ﺍﻟﻭﻀﻌﻴﺔ ﺤﺴﺎﺒﻴﺎ := f (x) - y 2x 1 - = 2x )2x - 2x ( x2 + 1 x2 + x2 + 1 )f (x = - 2x −2 x 3 ﺇﺫﻥ : x2 + 1 x ∞− ﺠﺩﻭل ﺍﻹﺸﺎﺭﺓ ( )f x - 2x : + −2 x 3 + ∞0 + + x2 + 1 -f ( x)-2x + - ﻟﻤﺎ (C) : x ! 0ﻴﻘﻊ ﺘﺤﺕ ∆) (
ﻟﻤﺎ (C) : x 0ﻴﻘﻊ ﻓﻭﻕ ∆) ( ﻟﻤﺎ (C) x 0ﻴﻘﻁﻊ ∆ ﻓﻲ ﺍﻟﻨﻘﻁﺔ ﺫﺍﺕ ﺍﻟﻔﺎﺼﻠﺔ 0ﻭﻫﻲ ﺍﻟﻤﺒﺩﺃ ( ). O ﺍﻻﺴﺘﻨﺘﺎﺝ :ﺍﻟﻤﻤﺎﺱ ∆ ﻴﺨﺘﺭﻕ ﺍﻟﺒﻴﺎﻥ ∆ ﻓﻲ ﻨﻘﻁﺔ ﺍﻟﺘﻤﺎﺱ Oﻭ ﺘﺩﻋﻰ ﺍﻟﻨﻘﻁﺔ Oﻨﻘﻁﺔ ﺍﻨﻌﻁﺎﻑ( ) ( ). ﺍﻟﻨﺸﺎﻁ : 2 fﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ ﻤﻌﺭﻓﺔ ﻋﻠﻰ \ ﺒﺎﻟﻌﺒﺎﺭﺓ ( )f x = x2 + 4 : ﻤﻥ ﺃﺠل x0ﻭ ( ) ( )h f x0 x0 + h - f (1ﺍﺤﺴﺏ ﺍﻟﻨﺴﺒﺔ : h ﻋﺩﺩﺍﻥ ﺤﻘﻴﻘﻴﺎﻥ ﻤﻊ . h ≠ 0ﺜﻡ ﺒﻴﻥ ﺃﻥ :f ( x0 + )h - f ) ( x0 = 2x0 + h h ( x0 + h)2 + 4 + x02 + 4 limﻤﺎﺫﺍ ﺘﻤﺜل ﻫﺫﻩ ﺍﻟﻨﻬﺎﻴﺔ( ) ( ).f x0 h→0 x0 + h - f (2ﺍﺴﺘﻨﺘﺞ : h (3ﺍﺴﺘﻨﺘﺞ ﻋﺒﺎﺭﺓ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ . f ﺍﻟﺤل : -1ﺤﺴﺎﺏ ﺍﻟﻨﺴﺒﺔ : ﺍﻟﺩﺍﻟﺔ fﻤﻌﺭﻓﺔ ﻋﻠﻰ \ ﻭ ﻟﺩﻴﻨﺎ :f ( x0 + h) - f ( x0 ) = ( x0 + h)2 + 4 - x02 + 4 hh ( x0+ h)2 + 4 - x02 + 4 ( x0+ h)2 + 4 + x02 + 4 = h ( x0 + h)2 + 4 + x02 + 4
( )= ( x0 + h)2 + 4 - x02 + 4 ( x0 + h)2 + 4 + h x02 + 4 = x02 + 2x0h + h2 + 4 - x02 - 4 ( x0 + h)2 + 4 + h x02 + 4 = 2x0h + h2 ( x0 + h)2 + 4 + h x02 + 4 = h ( 2x0 + h) ( x0 + h)2 + 4 + h x02 + 4 f ( x0 + h) - f ( x0 ) = 2x0h + h2 : ﻭﻋﻠﻴﻪ h ( x0 + h)2 + 4 + x02 + 4lim f ( x0 + h) - f ( x0 ) = lim : ﺍﺴﺘﻨﺘﺎﺝ ﺍﻟﻨﻬﺎﻴﺔ-2 h→0h→0 h 2x0h + h2 ( x0 + h)2 + 4 + x02 + 4 = 2x0 x02 + 4 + x02 + 4 = 2x0 2 x02 + 4
lim f ( x0 + )h - ) f ( x0 = 2x0 ﺇﺫﻥ : x02 + 4h→0 h ﻫﺫﻩ ﺍﻟﻨﻬﺎﻴﺔ ﺘﻤﺜل ﺍﻟﻌﺩﺩ ﺍﻟﻤﺸﺘﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ . x0 -2ﺍﺴﺘﻨﺘﺎﺝ ﻋﺒﺎﺭﺓ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ : f ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ fﻤﻌﺭﻓﺔ ﻋﻠﻰ \ ﺒﺎﻟﻌﺒﺎﺭﺓ : f ′(x) = x x2 + 4 ﺍﻟﻨﺸﺎﻁ : 3 ﺇﻟﻴﻙ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ ) (Cﻟﻠﺩﺍﻟﺔ fﻭ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ C′ﻟﺩﺍﻟﺘﻬﺎ) ( y ﺍﻟﻤﺸﺘﻘﺔ f ′ﻋﻠﻰ \ .(c') 2 -1ﺍﺩﺭﺱ ﺇﺸﺎﺭﺓ ) f ′( xﺒﻴﺎﻨﻴﺎ. 1 -2ﻋﻴﻥ ﺍﺘﺠﺎﻩ ﺘﻐﻴﺭ ﺍﻟﺩﺍﻟﺔ . f -2 -1 0 1 2 x ﺒﻴﻥ ﺍﺘﺠﺎﻩ ﺍﺴﺘﻨﺘﺞ ﺍﻟﻌﻼﻗﺔ -3 -1 ﺇﺸﺎﺭﺓ ﺩﺍﻟﺘﻬﺎ ﺘﻐﻴﺭ ﺍﻟﺩﺍﻟﺔ fﻭ -2 ﺍﻟﻤﺸﺘﻘﺔ. -3(c) -4
ﺍﻟﺤل : -1ﺩﺭﺍﺴﺔ ﺇﺸﺎﺭﺓ ( ): f x′∞x - -1 ∞1 +)f ′(x + - + -2ﺘﻌﻴﻴﻥ ﺍﺘﺠﺎﻩ ﺘﻐﻴﺭ ﺍﻟﺩﺍﻟﺔ : f ﺍﻟﺩﺍﻟﺔ fﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﻜل ﻤﻥ ﺍﻟﻤﺠﺎﻟﻴﻥ -∞ ; -1ﻭ ∞[ [ ] ]1 ; + ﻭﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﺍﻟﻤﺠﺎل [ ]-1 ; 1 -3ﺍﻻﺴﺘﻨﺘﺎﺝ :ﺇﺫﺍ ﻜﺎﻨﺕ f ′ﻤﻭﺠﺒﺔ ﺘﻤﺎﻤﺎ ﺃﻭ ﻤﻌﺩﻭﻤﺔ ﻋﻨﺩ ﻗﻴﻡ ﻤﻌﺯﻭﻟﺔ ﻤﻥ ﺍﻟﻤﺠﺎل Iﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ fﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﺍﻟﻤﺠﺎل .I ﻭﺇﺫﺍ ﻜﺎﻨﺕ f ′ﺴﺎﻟﺒﺔ ﺘﻤﺎﻤﺎ ﺃﻭ ﻤﻌﺩﻭﻤﺔ ﻋﻨﺩ ﻗﻴﻡ ﻤﻌﺯﻭﻟﺔ ﻤﻥ ﻤﺠﺎل Jﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ fﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﺍﻟﻤﺠﺎل . J
-1ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ ﻋﻨﺩ ﻋﺩﺩ ﺘﻌﺭﻴﻑ : 1 fﺩﺍﻟﺔ ﻤﻌﺭﻓﺔ ﻋﻠﻰ ﻤﺠﺎل . D fﻨﻘﻭل ﻋﻠﻥ ﺍﻟﺩﺍﻟﺔ fﺃﻨﻬﺎ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ ﺍﻟﻌﺩﺩ x0ﺇﺫﺍ ﻭﺍﻓﻕ ﺇﺫﺍ lim f ( x0 + h) - f ( x0 ) = A ﻜﺎﻥ ; A ∈ \ : h→0 h ﺍﻟﻌﺩﺩ Aﻴﺴﻤﻰ ﺍﻟﻌﺩﺩ ﺍﻟﻤﺸﺘﻕ ﻟﻠﺩﺍﻟﺔ . f ﻭ ﻨﺭﻤﺯ ﻟﻪ ﺒﺎﻟﺭﻤﺯ ( ). f x′ ﻤﺜﺎل :1 f : x 6ﻋﻨﺩ ﺍﻟﻌﺩﺩ . 2 1 ﺍﺩﺭﺱ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ : x 1 f )(2 = 2 . ﺍﻟﺤل D f = \* : f (2+ h) - f )(2 1 - 1 2-2-h 2 )2 (2 + hlim h = lim 2+h = lim h hh→0 h→0 h→0 = lim -h × 1 = lim -1 = - 1 h→0 )2 (2 + h h h→0 )2 (2 + h 4 ( )f ′ 2 = - 1 ﻭﻋﻠﻴﻪ fﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ 2ﺤﻴﺙ : 4 ﻤﺜﺎل : 2 ﺍﺩﺭﺱ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ 0ﻟﻠﺩﺍﻟﺔ x 6 x : f \ = f ( x) = x , x ≥ 0 . Df ﺍﻟﺤل : f ( )x = x , x ≤ 0
• lim f (h) - f (0) = lim h - 0 = 1 > h >h h→0 h→0lim f (h) - f (0) = lim -h = -1 < h <hh→0 h→0 ﻭﻤﻨﻪ ﻟﻴﺱ ﻟﻠﻨﺴﺒﺔ ﻨﻬﺎﻴﺔ ﻭ ﻋﻠﻴﻪ fﻏﻴﺭ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ . 0 ﺍﻟﺘﻔﺴﻴﺭ ﺍﻟﺒﻴﺎﻨﻲ :ﺇﺫﺍ ﻗﺒﻠﺕ ﺍﻟﺩﺍﻟﺔ fﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ x0ﻓﺈﻥ ﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ ﻴﻘﺒل ﻓﻲ ﺍﻟﻨﻘﻁﺔ ( ( ))A x0 ; f x0 ﻤﻤﺎﺴﺎ ﻤﻌﺎﻤل ﺘﻭﺠﻴﻬﻪ . f ′ xﻭﻴﻘﺒل ﻜﻤﻌﺎﺩﻟﺔ ( ): ) y = f ( x0 ) × ( x - x0 ) + f ( x0 ﺍﻟﺘﻔﺴﻴﺭ ﺍﻟﻌﺩﺩﻱ : ﺇﺫﺍ ﻗﺒﻠﺕ ﺍﻟﺩﺍﻟﺔ fﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ x0ﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ ﺍﻟﺘﺂﻟﻔﻴﺔ : x 6 f x x - x0 + f x0ﻫﻲ ﺘﻘﺭﻴﺏ ﺘﺂﻟﻔﻲ ﻟﻠﺩﺍﻟﺔ fﺒﺠﻭﺍﺭ ( ) ( ) ( ). x0 ﺃﻱ ﺃﻥ ﺍﻟﻤﻤﺎﺱ ﻋﻨﺩ x0ﻫﻭ ﺃﺤﺴﻥ ﺘﻘﺭﻴﺏ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ . x0 ﺍﻟﺘﻔﺴﻴﺭ ﺍﻟﻔﺯﻴﺎﺌﻲ : ﺇﺫﺍ ﻜﺎﻥ ﻗﺎﻨﻭﻥ ﺍﻟﺤﺭﻜﺔ x 6 x t :ﻓﺈﻥ x′ t0 :ﻫﻭ ﺍﻟﺴﺭﻋﺔ) ( ) ( ﺍﻟﻠﺤﻅﻴﺔ ﻓﻲ ﺍﻟﻠﺤﻅﺔ . to ﺇﺫﺍ ﻜﺎﻥ x 6 v tﻫﻭ ﻗﺎﻨﻭﻥ ﺤﺭﻜﺔ ﻓﺈﻥ ( ): v′ t0ﻫﻭ ﺍﻟﺘﺴﺎﺭﻉ ﻓﻲ ﺍﻟﻠﺤﻅﺔ ( ). to ﺘﻌﺭﻴﻑ : 2 fﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ ﻤﻌﺭﻓﺔ ﻋﻠﻰ ﺍﻷﻗل ،ﻋﻠﻰ ﻤﺠﺎل ﻤﻥ ﺍﻟﺸﻜل x0 ; x0 + αﺤﻴﺙ x0و αﻋﺩﺩﺍﻥ ﺤﻘﻴﻘﻴﺎﻥ ﻤﻊ α > 0ﻨﻘﻭل ﻋﻥ ﺍﻟﺩﺍﻟﺔ fﺃﻨﻬﺎ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ x0ﻤﻥ ﺍﻟﻴﻤﻴﻥ ﺇﺫﺍ ﻭﻓﻕ ﺇﺫﺍ ﻜﺎﻨﺕ : lim f ( x0 )+ h -f ) ( x0 = A1 h→0 h h>0
ﺤﻴﺙ A1ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻭﻴﺴﻤﻰ ﺍﻟﻌﺩﺩ ﺍﻟﻤﺸﺘﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ x0ﻤﻥ ﺍﻟﻴﻤﻴﻥ ﺘﻌﺭﻴﻑ : 3 fﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ ﻤﻌﺭﻓﺔ ﻋﻠﻰ ﺍﻷﻗل ،ﻋﻠﻰ ﻤﺠﺎل ﻤﻥ ﺍﻟﺸﻜل x0 - α ; x0 ﺤﻴﺙ x0و αﻋﺩﺩﺍﻥ ﺤﻘﻴﻘﻴﺎﻥ ﻤﻊ α > 0ﻨﻘﻭل ﻋﻥ ﺍﻟﺩﺍﻟﺔ fﺃﻨﻬﺎ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻥ x0ﻤﻥ ﺍﻟﻴﺴﺎﺭ ﺇﺫﺍ ﻭﺍﻓﻕ ﺇﺫﺍ ﻜﺎﻨﺕ : lim f ( x0 + )h - f ) ( x0 = A2 h→0 h h<0 ﺤﻴﺙ A 2ﻋﺩﺩ ﺤﻘﻴﻘﻲ ﻭﻴﺴﻤﻰ ﺍﻟﻌﺩﺩ ﺍﻟﻤﺸﺘﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ x0ﻤﻥ ﺍﻟﻴﺴﺎﺭ ﻤﺜﺎل : 1ﺍﻟﺩﺍﻟﺔ x 6 x x : fﻗﺎﺒﻠﻴﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻓﻲ 0ﻋﻠﻰ ﺍﻟﻴﻤﻴﻥ ﻷﻨﻬﺎ ﻤﻌﺭﻓﺔ ﻋﻠﻰ [∞ [0 ; +ﻭlim f (h) - f (0) = lim h h = lim h = 0h→0 h h→0 h h→0h>0 h>0 h>0 ﻤﺜﺎل : 2ﺍﻟﺩﺍﻟﺔ x 6 4 - x : fﻏﻴﺭ ﻗﺎﺒﻠﻴﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻓﻲ 4ﻋﻠﻰ ﺍﻟﻴﺴﺎﺭ ﻷﻥ :lim f (h) - f (0) = lim -h = lim hh→0 h h→0 h h→0 -h . -hh<0 h<0 h<0 ∞= lim 1 = - − -hh→0 h<0 ﻤﺜﺎل : 3ﺍﻟﺩﺍﻟﺔ x 6 x : fﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻓﻲ 0ﻋﻠﻰ ﺍﻟﻴﻤﻴﻥ ﻷﻨﻬﺎ ﻤﻌﺭﻓﺔ ﻋﻠﻰ \ ﻭ lim h - 0 = lim h = 1 h→0 h h→0 h h>0 h>0 ﻭﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻓﻲ 0ﻋﻠﻰ ﺍﻟﻴﺴﺎﺭ ﻷﻥ :
lim h - 0 = = lim -h = -1h→0 h h→0 hh<0 h<0 ﻟﻜﻥ ﺍﻟﺩﺍﻟﺔ fﻏﻴﺭ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ . 0 ﻨﺘﻴﺠﺔ :ﺘﻜﻭﻥ ﺍﻟﺩﺍﻟﺔ fﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻓﻲ x0ﺇﺫﺍ ﻭﺍﻓﻕ ﺇﺫﺍ ﻗﺒﻠﺕ ﻫﺫﻩ ﺍﻟﺩﺍﻟﺔ ﻨﻔﺱ ﺍﻟﻌﺩﺩ ﺍﻟﻤﺸﺘﻕ ﻤﻥ ﺍﻟﻴﻤﻴﻥ ﻭ ﻤﻥ ﺍﻟﻴﺴﺎﺭ ﻓﻲ . x0 ﺍﻻﺴﺘﻤﺭﺍﺭﻴﺔ ﻭ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ : ﻤﺒﺭﻫﻨﺔ :ﺇﺫﺍ ﻜﺎﻨﺕ fﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻤﻥ ﺃﺠل x0ﺘﻜﻭﻥ ﻫﺫﻩ ﺍﻟﺩﺍﻟﺔ ﻤﺴﺘﻤﺭﺓ ﻋﻨﺩ . x0 ﻤﻼﺤﻅﺔ : ﻋﻜﺱ ﻫﺫﻩ ﺍﻟﻨﻅﺭﻴﺔ ﻏﻴﺭ ﺼﺤﻴﺢ .ﻓﻤﺜﻼ ﺍﻟﺩﺍﻟﺔ x 6 xﻤﺘﺴﻤﺭﺓ ﻋﻨﺩﻩ ﻭ ﻟﻜﻨﻬﺎ ﻏﻴﺭ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ 0ﻜﻤﺎ ﺴﺒﻕ. ﺤﺎﻻﺕ ﺨﺎﺼﺔ : limﻓﺈﻥ ﺍﻟﺘﻤﺜﻴل) ( ) ( h→0f x0 + h - f x0 * ﺇﺫﺍ ﻜﺎﻨﺕ = +∞ : h ﺍﻟﺒﻴﺎﻨﻲ ﻟﻠﺩﺍﻟﺔ fﻴﻘﺒل ﻤﻤﺎﺴﺎ ﻋﻨﺩ ﺍﻟﻨﻘﻁﺔ ﺫﺍﺕ ﺍﻟﻔﺎﺼﻠﺔ x0ﻴﻭﺍﺯﻱ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﺘﺭﺘﻴﺏ x0 * ﺇﺫﺍ ﻗﺒﻠﺕ ﺍﻟﺩﺍﻟﺔ fﺍﻻﺸﺘﻘﺎﻕ ﻓﻲ x0ﻤﻥ ﺍﻟﻴﻤﻴﻥ ﻓﺈﻥ ﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ ﻴﻘﺒل ﻨﺼﻑ ﺍﻟﻤﻤﺎﺱ ﻤﻥ ﺍﻟﻴﻤﻴﻥ ﻭ ﻫﻭ ﻤﻌﺭﻑ ﻜﻤﺎ ﻴﻠﻲ : ﻤﻥ ﺃﺠل y - f ( x0 ) = A1 ( x - x0 ) : x ≥ x0x0
ﺤﻴﺙ A1ﻫﻭ ﺍﻟﻌﺩﺩ ﺍﻟﻤﺸﺘﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ x0ﻤﻥ ﺍﻟﻴﻤﻴﻥ .* ﺇﺫﺍ ﻗﺒﻠﺕ ﺩﺍﻟﺔ fﺍﻻﺸﺘﻘﺎﻕ ﻓﻲ x0ﻤﻥ ﺍﻟﻴﺴﺎﺭ ﻓﺈﻥ ﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ ﻴﻘﺒلﻨﺼﻑ ﺍﻟﻤﻤﺎﺱ ﻤﻥ ﺍﻟﻴﺴﺎﺭ ﻭ ﻫﻭ ﻤﻌﺭﻑ ﻜﻤﺎ ﻴﻠﻲ :ﻤﻥ ﺃﺠل y - f ( x0 ) = A1 ( x - x0 ) : x ≤ x0x0 ﺤﻴﺙ A 2ﻫﻭ ﺍﻟﻌﺩﺩ ﺍﻟﻤﺸﺘﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ x0ﻤﻥ ﺍﻟﻴﺴﺎﺭ . * ﺇﺫﺍ ﻜﺎﻥ ﺍﻟﻌﺩﺩﺍﻥ ﺍﻟﻤﺸﺘﻘﺎﻥ A1ﻭ A 2 ﻤﺨﺘﻠﻔﺎﻥ ﻓﺈﻥ ﺍﻟﻨﻘﻁﺔ ﺫﺍﺕ ﺍﻟﻔﺎﺼﻠﺔ x0ﺘﺩﻋﻰ ﻨﻘﻁﺔ ﺯﺍﻭﻴﺔx0 . -2ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﺩﺍﻟﺔ :ﺇﺫﺍ ﻜﺎﻨﺕ ﺍﻟﺩﺍﻟﺔ fﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ ﻜل ﻋﺩﺩ xﻤﻥ ﻤﺠﺎل Iﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ ( )x 6 f ′ x :ﺘﺴﻤﻰ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ fﻋﻠﻰ . Iﻓﺈﺫﺍ ﻭﻀﻌﻨﺎ ( )y = f x :( )dyﺒﺎﻟﺭﻤﺯfx ﻓﺈﻨﻨﺎ ﻨﺭﻤﺯ ﺇﻟﻰdxdydx )= f ′(x ﻭﻨﻜﺘﺏ :ﺃﻱ ﺃﻥ dy = f ′( x ) dx :
-ﺤﺴﺎﺏ ﺍﻟﻤﺸﺘﻘﺎﺕ : xﻤﺸﺘﻘﺎﺕ ﺍﻟﺩﻭﺍل ﺍﻟﻤﺄﻟﻭﻓﺔ :ﺸﺭﻁ ﻤﺠﺎل ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﺍﻟﺩﺍﻟﺔ ﺍﻟﺘﻁﺒﻴﻕ 0 x → 0 kﺜﺎﺒﺕ ; x → k x → 1 \ x → nxn-1 ; x → x \ x → -n *` ∈ x → xn , n *\ x → 1 x → 1 *` ∈ , n \*+ 2x xn x → x\ x → cosx x → sinx \ x → -sinx x → cosxcosx ≠ 0 x → tanx x → 1 cos2 x xﻋﻤﻠﻴﺎﺕ ﻋﻠﻰ ﺍﻟﺩﻭﺍل ﺍﻟﻤﺸﺘﻘﺔ :ﺇﺫﺍ ﻜﺎﻨﺕ fﻭ gﺩﺍﻟﺘﺎﻥ ﻗﺎﺒﻠﺘﺎﻥ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﻤﺠﺎل a ; bﻭ ﻜﺎﻥ λﻋﺩﺩﺍ ﺤﻘﻴﻘﻴﺎ ﻓﺈﻥ ] [: (1ﺍﻟﺩﻭﺍل f + gﻭ f × gﻭ λ fﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ ] [a ; b ﺤﻴﺙ (λ f )′ = λ f ′ :( f + g)′ = f ′ + g′ ; ( f . g)′ = f ′. g + f .g′
f 1 gﺘﻘﺒﻼﻥ ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ gﻭ] [ ] [a ; b (2ﺇﺫﺍ ﻜﺎﻥ gﻻ ﻴﻨﻌﺩﻡ ﻋﻠﻰ a ; bﻓﺈﻥ : ﺒﺤﻴﺙ : 1 ′ = -g′ ; f ′ = f′ .g-f . g′ g g2 g g2 -ﻤﺸﺘﻕ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺭﻜﺒﺔ : ﻤﺒﺭﻫﻨﺔ :ﺇﺫﺍ ﻜﺎﻨﺕ uﺩﺍﻟﺔ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ x0ﻭ fﺩﺍﻟﺔ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ u x0ﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ) ( fouﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ x0ﻭﻟﺩﻴﻨﺎ : ( fou)′ ( x0 ) = u′( x0 ) . f ′ u( x0 ) ﻤﺜﺎل : ( )g x = sin 2x + π ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ gﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ : 3 ﻋﻴﻥ ﻋﺒﺎﺭﺓ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ g′ﻟﻠﺩﺍﻟﺔ . g ﺍﻟﺤل : ﺍﻟﺩﺍﻟﺔ gﻫﻲ ﻤﺭﻜﺏ ﺍﻟﺩﺍﻟﺘﻴﻥ uﻭ fﺤﻴﺙ : f ( x) = sin x ﻭ )u( x = 2x + π 3)g( x = )u′( x .f′ u( x) = 2 . cos 2x + π ﻭﻋﻠﻴﻪ : 3 ﻨﺘﺎﺌﺞ : u (1ﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﻤﺠﺎل . I ﻤﺸﺘﻘﺔ ﺍﻟﺩﺍﻟﺔ fﺤﻴﺙ n ∈ `*-{1} , f ( x ) = u( x )n :
ﻫﻲ ﺍﻟﺩﺍﻟﺔ f ′ﺤﻴﺙ [ ]f ′( x ) = n . u(x) n−1 .u′(x) : ﻷﻥ ﺍﻟﺩﺍﻟﺔ fﻫﻲ ﻤﺭﻜﺏ ﺍﻟﺩﺍﻟﺘﻴﻥ uﻭ gﺤﻴﺙ ( )g x = xn : ﻤﺜﺎل : ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ fﺤﻴﺙ ( ) ( )f x = x2 + 1 4 :ﻫﻲ ﺍﻟﺩﺍﻟﺔ f ′ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ \ ﺒﺎﻟﻌﺒﺎﺭﺓ ( ) ( ) ( )f ′ x = u 2x x2 + 1 3 : ﺇﺫﻥ ( )f ′( x) = 8x x2 + 1 3 : u (2ﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﻤﺠﺎل Iﻭﻤﻭﺠﺒﺔ ﺘﻤﺎﻤﺎ ﺃﻴﻀﺎ.ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ fﺤﻴﺙ ( ) ( )f x = u x :( ) ( )f ′ x = u′ x ﻫﻲ ﺍﻟﺩﺍﻟﺔ f ′ﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ Iﺒﺎﻟﻌﺒﺎﺭﺓ : ( )2 u xﻷﻥ ﺍﻟﺩﺍﻟﺔ fﻫﻲ ﻤﺭﻜﺏ ﺍﻟﺩﺍﻟﺘﻴﻥ uﻭ gﺤﻴﺙ ( )g x = x : ﻤﺜﺎل :ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ x 6 x2 + 4 : fﻫﻲ ﺍﻟﺩﺍﻟﺔ f ′( )f ′ x = 2x ﺍﻟﻤﻌﺭﻓﺔ ﻜﻤﺎ ﻴﻠﻲ : 2 x2 + 4 = )f ′(x x ﺇﺫﻥ x2 + 4 : a (3ﻭ bﻋﺩﺩﺍﻥ ﺤﻘﻴﻘﻴﺎﻥ ﺤﻴﺙ . a ≠ 0ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ ( )x 6 sin ax + b : f ﻫﻲ ﺍﻟﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﻜﻤﺎ ﻴﻠﻲ ( ) ( )f ′ x = a cos ax + b :ﻷﻥ ﺍﻟﺩﺍﻟﺔ fﻫﻲ ﻤﺭﻜﺏ ﺍﻟﺩﺍﻟﺘﻴﻥ x 6 ax + b :ﻭ x 6 sin x a (4ﻭ bﻋﺩﺩﺍﻥ ﺤﻘﻴﻘﻴﺎﻥ ﺤﻴﺙ . a ≠ 0
ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ ( )x 6 cos ax + b : f ﻫﻲ ﺍﻟﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﻜﻤﺎ ﻴﻠﻲ ( ) ( )f ′ x = -a sin ax + b : ﻷﻥ ﺍﻟﺩﺍﻟﺔ fﻫﻲ ﻤﺭﻜﺏ ﺍﻟﺩﺍﻟﺘﻴﻥ x 6 ax + b :ﻭ x 6 cos x ﺍﺘﺠﺎﻩ ﺘﻐﻴﺭ ﺩﺍﻟﺔ : ﻤﺒﺭﻫﻨﺔ : ﻟﺘﻜﻥ ﺩﺍﻟﺔ fﻭﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﻤﺠﺎل D fﻭ f ′ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ. xﺇﺫﺍ ﻜﺎﻨﺕ f ′ﻤﻭﺠﺒﺔ ﺘﻤﺎﻤﺎ )ﻴﻤﻜﻥ ﺃﻥ ﺘﻜﻭﻥ f ′ﻤﻌﺩﻭﻤﺔ ﻤﻥ ﺃﺠل ﻗﻴﻡ ﻤﻨﻌﺯﻟﺔ ﻤﻥ ( D fﻋﻠﻰ ﺍﻟﻤﺠﺎل D fﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ fﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﺍﻟﻤﺠﺎل . D f xﻤﻥ ﺃﺠل ﻗﻴﻡ ﻤﻨﻌﺯﻟﺔ ﻤﻥ ( D fﻋﻠﻰ ﺍﻟﻤﺠﺎل D fﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ fﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﺍﻟﻤﺠﺎل . Df xﺇﺫﺍ ﻜﺎﻨﺕ f ′ﻤﻌﺩﻭﻤﺔ ﻋﻠﻰ ﺍﻟﻤﺠﺎل D fﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ fﺜﺎﺒﺘﺔ ﻋﻠﻰ ﺍﻟﻤﺠﺎل . D f ﺍﻟﻘﻴﻤﺔ ﺍﻟﺤﺩﻴﺔ ﺍﻟﻤﺤﻠﻴﺔ ﻟﺩﺍﻟﺔ : ﻤﺒﺭﻫﻨﺔ : ﻟﺘﻜﻥ fﺩﺍﻟﺔ ﻤﻌﺭﻓﺔ ﻭ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﻤﺠﺎل Iﻭ f ′ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ.ﺇﺫﺍ ﺍﻨﻌﺩﻤﺕ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ f ′ﻋﻨﺩ ﻗﻤﺔ Cﻤﻥ Iﻤﻐﻴﺭﺓ ﺇﺸﺎﺭﺘﻬﺎ ﻓﺈﻨﻪ ﻴﻭﺠﺩ ﻤﺠﺎل I′ﻤﺤﺘﻭﻯ ﻓﻲ I ﻴﺸﻤل Cﺘﻘﺒل ﻓﻴﻪ fﻗﻴﻤﺔ ﺤﺩﻴﺔ . f Cﺘﺴﻤﻰ f Cﻗﻴﻤﺔ ﺤﺩﻴﺔ ﻤﺤﻠﻴﺔ ( ) ( ). ﻤﻼﺤﻅﺔ : xﻴﻤﻜﻥ ﻭﺠﻭﺩ ﻋﺩﺓ ﻗﻴﻡ ﺤﺩﻴﺔ ﻤﺤﻠﻴﺔ ﻋﻠﻰ . I xﺇﺫﺍ ﺍﻨﻌﺩﻤﺕ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ f ′ﻋﻨﺩ ﻗﻴﻤﺔ Cﻤﻥ Iﻓﺈﻥ ﺍﻟﺭﺴﻡ ﺍﻟﺒﻴﺎﻨﻲ ﻟﻠﺩﺍﻟﺔ fﻴﻘﺒل ﻤﻤﺎﺴﺎ ﻤﻭﺍﺯﻴﺎ ﻟﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﻔﻭﺍﺼل ﻋﻨﺩ ﺍﻟﻨﻘﻁﺔ ﺍﻟﺘﻲ ﻓﺎﺼﻠﺘﻬﺎ . C ﺍﻟﻤﺸﺘﻘﺎﺕ ﺍﻟﻤﺘﺘﺎﺒﻌﺔ ﻟﺩﺍﻟﺔ : ﻟﺘﻜﻥ fﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ f ′ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ ﺍﻟﻤﺠﺎل . I ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﺍﻟﺔ f ′ﺘﺩﻋﻰ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﺍﻟﺜﺎﻨﻴﺔ ﻟﻠﺩﺍﻟﺔ fﻭ ﻨﺭﻤﺯ ﻟﻬﺎ ﺒﺎﻟﺭﻤﺯ . f ′′
ﻭ ﺇﺫﺍ ﻜﺎﻨﺕ f ′′ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ Iﻓﺈﻥ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ ﺘﺩﻋﻰ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﺍﻟﺜﺎﻟﺜﺔ ﺃﻭ ﺍﻟﺩﺍﻟﺔﺍﻟﻤﺸﺘﻘﺔ ﺫﺍﺕ ﺍﻟﺭﺘﻴﺒﺔ .ﻟﻠﺩﺍﻟﺔ fﻭﻨﺭﻤﺯ ﻟﻬﺎ ﺒﺎﻟﺭﻤﺯ f ′′′ﻭ ﻫﻜﺫﺍ ﻴﻤﻜﻥ ﺘﻌﺭﻴﻑ ﺍﻟﺩﻭﺍل ﺍﻟﻤﺸﺘﻘﺔ ﺍﻟﺘﻲ ﺭﺘﺒﺘﻬﺎ n ، ... ، 6 ، 5 ، 4ﺤﻴﺙ nﻋﺩﺩ ﻁﺒﻴﻌﻲ n ≥ 4 ،ﻭ ﺍﻟﺘﻲ ﻨﺭﻤﺯ ﻟﻬﺎ ﻜﻤﺎ ﻴﻠﻲ ). f (4) , f (5) , . . . , f (n ﺘﺩﻋﻰ ﺍﻟﺩﻭﺍل ﺍﻟﻤﺸﺘﻘﺔ ) f (1) , f (2) , . . . , f (nﺍﻟﺩﻭﺍل ﺍﻟﻤﺸﺘﻘﺔ ﺍﻟﻤﺘﺘﺎﺒﻌﺔ ﻟﻠﺩﺍﻟﺔ . f ﻤﺜﺎل : ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺫﺍﺕ ﺍﻟﻤﺘﻐﻴﺭ xﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ : f ( x) = x4 - 4x3 + 12x + 6 -ﻋﻴﻥ ﻜل ﻤﻥ ). f ′, f ′′, f ′′′, f (4) , f (5 ﺍﻟﺤل : ﺍﻟﺩﺍﻟﺔ fﻫﻲ ﺩﺍﻟﺔ ﻜﺜﻴﺭﺓ ﺤﺩﻭﺩ ﻓﻬﻲ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ \ ﺤﻴﺙ : f ′( x) = 4x3 + 12x2 + 12 ﺍﻟﺩﺍﻟﺔ f ′ﻫﻲ ﺩﺍﻟﺔ ﻜﺜﻴﺭ ﺤﺩﻭﺩ ﻓﻬﻲ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ \ ﺤﻴﺙ : f ′′( x) = 12x2 - 24 ﺍﻟﺩﺍﻟﺔ f ′′ﻫﻲ ﺩﺍﻟﺔ ﻜﺜﻴﺭ ﺤﺩﻭﺩ ﻓﻬﻲ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ \ ﺤﻴﺙ : f ′′′( x) = 24x ﺍﻟﺩﺍﻟﺔ f ′′′ﻫﻲ ﺩﺍﻟﺔ ﻜﺜﻴﺭ ﺤﺩﻭﺩ ﻓﻬﻲ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ \ ﺤﻴﺙ : f (4) ( x ) = 24 ﺍﻟﺩﺍﻟﺔ ) f (4ﻫﻲ ﺩﺍﻟﺔ ﻜﺜﻴﺭ ﺤﺩﻭﺩ ﻓﻬﻲ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ \ ﺤﻴﺙ : f ((5) x ) = 0
ﻨﻘﻁﺔ ﺍﻻﻨﻌﻁﺎﻑ : ﺘﻌﺭﻴﻑ : ﻨﻘﻁﺔ ﺍﻨﻌﻁﺎﻑ ﻫﻲ ﻨﻘﻁﺔ ﻴﺨﺘﺭﻕ ﺍﻟﻤﻤﺎﺱ ﻓﻴﻬﺎ ﺍﻟﻤﻨﺤﻨﻲ. ﻨﺘﻴﺠﺔ :ﺇﺫﺍ ﻜﺎﻨﺕ ﺍﻟﺩﺍﻟﺔ fﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻤﺭﺘﻴﻥ ﻋﻠﻰ ﻤﺠﺎل ﻤﻔﺘﻭﺡ ﻴﺸﻤل x0ﻭ ﺇﺫﺍ ﺍﻨﻌﺩﻤﺕ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ ﺍﻟﺜﺎﻨﻴﺔ ﻤﻥ ﺃﺠل x0ﻤﻐﻴﺭﺓ ﺇﺸﺎﺭﺘﻬﺎ ﻓﺈﻥ ﺍﻟﻨﻘﻁﺔ M0ﺫﺍﺕ ﺍﻟﻔﺎﺼﻠﺔ x0ﻫﻲ ﻨﻘﻁﺔ ﺍﻨﻌﻁﺎﻑ ﻟﻠﻤﻨﺤﻨﻲ ﺍﻟﻤﻤﺜل ﻟﻠﺩﺍﻟﺔ . f ﺍﻟﻤﻌﺎﺩﻻﺕ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ : fﺩﺍﻟﺔ ﻋﺩﺩ ﻤﺘﻐﻴﺭﺍﺘﻬﺎ n ∈ ` , n + 1 ﻨﺴﻤﻲ ﻤﻌﺎﺩﻟﺔ ﺘﻔﺎﻀﻠﻴﺔ ﻤﻥ ﺍﻟﺭﺘﺒﺔ nﻜل ﻤﻌﺎﺩﻟﺔ ﻤﻥ ﺍﻟﺸﻜل : y(n) = f x , u , y′ , . . . , yn-1 ﺤﻴﺙ yﻫﻭ ﺍﻟﻤﺠﻬﻭل y(n) , y(n-1) , . . . , y′′ , y′ﻫﻲ ﺼﻭﺭ ﺍﻟﻤﺸﺘﻘﺎﺕ ﺍﻟﻤﺘﺘﺎﺒﻌﺔ ﻟﻠﺩﺍﻟﺔ . x 6 y :f ﻨﺴﻤﻲ ﺤﻼ ﻟﻠﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ ﻓﻲ ﺍﻟﻤﺠﺎل Iﻜل ﺩﺍﻟﺔ hﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ nﻤﺭﺓ ﻭﺘﺤﻘﻕ : h(n) ( x ) = f x , h( x ) , h( x ) , . . . , ( )h(n-1) x xﺍﻟﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ ﻤﻥ ﺍﻟﺸﻜل ( )y′ = f x : ﺤﻴﺙ fﻤﺄﻟﻭﻓﺔ .ﺤل ﻫﺫﻩ ﺍﻟﻤﻌﺎﺩﻟﺔ ﻋﻠﻰ ﻤﺠﺎل Iﻫﻭ ﺇﻴﺠﺎﺩ ﺩﺍﻟﺔ gﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ Iﻭ ﺘﺤﻘﻕ g′ x = f x :ﻤﻥ ﺃﺠل ﻜل xﻤﻥ ( ) ( )I
ﻤﺜﺎل : ﺤل ﺍﻟﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ y′ = 2x - 4ﻋﻠﻰ \ . \∈k ﺍﻟﺤل : ﺤل ﻫﺫﻩ ﺍﻟﻤﻌﺎﺩﻟﺔ ﻫﻭ ﺍﻟﺩﺍﻟﺔ gﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ \ ﺒﺎﻟﻌﺒﺎﺭﺓ g x = x2 - 4x + k :ﺤﻴﺙ) ( xﺍﻟﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ ﻤﻥ ﺍﻟﺸﻜل ( )y′′ = f x :ﺤﻴﺙ fﺩﺍﻟﺔ ﻤﺄﻟﻭﻓﺔ .ﺤل ﻫﺫﻩ ﺍﻟﻤﻌﺎﺩﻟﺔ ﻋﻠﻰ ﻤﺠﺎل Iﻫﻭ ﺇﻴﺠﺎﺩ ﺩﺍﻟﺔ gﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻤﺭﺘﻴﻥ ﻋﻠﻰ I ﻭ ﺘﺤﻘﻕ : ) g′′( x ) = f ( xﻤﻥ ﺃﺠل ﻜل xﻤﻥ . I ﻤﺜﺎل : ﺤل ﺍﻟﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ y′′ = x : ﺍﻟﺤل :( )g x = x3 \ ﺒﺎﻟﻌﺒﺎﺭﺓ + kx + c : ﺤل ﻫﺫﻩ ﺍﻟﻤﻌﺎﺩﻟﺔ ﻫﻭ ﺍﻟﺩﺍﻟﺔ gﺍﻟﻤﻌﺭﻓﺔ ﻋﻠﻰ 6 ﺤﻴﺙ C ∈ \ :ﻭ \ ∈ k xﺍﻟﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ ﻤﻥ ﺍﻟﺸﻜل y′′ = -w2y : ﺤل ﻫﺫﻩ ﺍﻟﻤﻌﺎﺩﻟﺔ ﻤﻥ ﺍﻟﺸﻜل y = a cos wx + b sin wx : ﺤﻴﺙ aﻭ bﻋﺩﺩﺍﻥ ﺤﻘﻴﻘﻴﺎﻥ ﺜﺎﺒﺘﺎﻥ. ﻤﺜﺎل :ﺤل ﺍﻟﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ y′′ + 25y = 0 : ﺍﻟﺤل :ﻟﺩﻴﻨﺎ y′′ = - 5 2 y :ﻭﻤﻨﻪ ﺤﻠﻬﺎ ﻫﻭ ( ): y = a cos 5x + b sin 5x
ﺘﻜﻨﻭﻟﻭﺠﻴﺎ ﺍﻹﻋﻼﻡ ﻭ ﺍﻻﺘﺼﺎل ﺍﻟﺘﻁﺒﻴﻕ : 1 ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ f (x) x4 2x2 :ﺘﺤﻘﻕ ﺒﺎﺴﺘﻌﻤﺎل ﺁﻟﺔ ﺒﻴﺎﻨﻴﺔ ﺍﻟﺘﻭﺍﻓﻕ ﺒﻴﻥ ﺍﺘﺠﺎﻩ ﺘﻐﻴﺭ ﺍﻟﺩﺍﺓ fﻭﺇﺸﺎﺭﺓ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ f c ﺍﻟﺤل :ﻨﻨﻘﺭ ﻋﻠﻰ ﺍﻟﺯﺭ : (1ﻭﻨﻜﺘﺏ ﻋﺒﺎﺭﺓ ﺍﻟﺩﺍﻟﺔ fﻓﻲ y1ﻭﻋﺒﺎﺭﺓ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ f cﻓﻲ y2ﻜﻤﺎ ﻴﻠﻲ : (2ﻨﻨﻘﺭ ﻋﻠﻰﻭﻨﺩﺨل ﺍﻟﻤﻌﻠﻭﻤﺎﺕ ﺍﻟﺘﺎﻟﻴﺔ ﻜﻤﺎ ﻴﻅﻬﺭ ﻋﻠﻰ ﺍﻟﺸﺎﺸﺔ : (3ﻨﻨﻘﺭ ﻋﻠﻰﻓﻨﺤﺼل ﺍﻟﺘﻤﺜﻴﻠﻴﻥ ﺍﻟﺒﻴﺎﻨﻴﻴﻥ ﻜﻤﺎ ﻴﻅﻬﺭ ﻋﻠﻰ ﺍﻟﺸﺎﺸﺔ (4ﻴﻤﻜﻥ ﺘﺤﺭﻴﻙ ﻨﻘﻁﺔ ﻤﻥ ﺍﻟﺒﻴﺎﻥ ﻟﻨﻼﺤﻅ ﺃﻨﻪ ﻜﻠﻤﺎ ﻜﺎﻨﺕ f c(x) ; 0 ﻜﺎﻨﺕ ﺍﻟﺩﺍﻟﺔ fﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻓﻤﺜﻼ ﻤﻥ ﺃﺠل x 0.43 f c(x) 1.39ﻭﻋﻠﻴﻪ f c(x) ; 0 :
ﺍﻟﺘﻁﺒﻴﻕ : 2ﺤﺴﺎﺏ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻟﺩﺍﻟﺔ ﺒﺎﺴﺘﻌﻤﺎل ﺍﻟﺒﺭﻤﺠﻴﺔ scientific workplace 3.0 (1ﻨﻨﻘﺭ ﻋﻠﻰ ﺍﻹﻴﻘﻭﻨﺔ ﺍﻟﺘﻲ ﺘﺤﻤل ﺍﻟﺤﺭﻑ Tﻓﻨﺤﺼل ﻋﻠﻰ ﺍﻟﺤﺭﻑ M ﻭ ﻫﺫﺍ ﻟﺘﺤﻭﻴل ﺍﻟﻜﺘﺎﺒﺔ ﻤﻥ ﺍﻟﻨﺹ ﺍﻷﺩﺒﻲ ﺇﻟﻰ ﺍﻟﻨﺹ ﺍﻟﺭﻴﺎﻀﻲ . (2ﻨﻜﺘﺏ ﻋﺒﺎﺭﺓ ﺍﻟﺩﺍﻟﺔ . (3ﻨﻨﻘﺭ ﻋﻠﻰ ﺍﻹﻴﻘﻭﻨﺔ . ﺜﻡ ﻨﺨﺘﺎﺭ ﻤﻨﻬﺎ . ﻓﺘﻅﻬﺭ ﻋﻠﺒﺔ ﺍﻟﺤﻭﺍﺭ ﺍﻟﺘﺎﻟﻴﺔ ﺍﻟﺘﻲ ﻨﻜﺘﺏ ﺒﺩﺍﺨﻠﻬﺎ ﺍﻟﻤﺘﻐﻴﺭ. (4ﺘﻅﻬﺭ ﺍﻟﺒﺭﻤﺠﻴﺔ ﻋﺒﺎﺭﺓ ﺍﻟﺩﺍﻟﺔ ﺍﻟﻤﺸﺘﻘﺔ ﻜﻤﺎ ﻫﻭ ﻓﻲ ﺍﻟﺼﻭﺭﺓ .
ﺘﻤـﺎﺭﻴﻥ ﻭ ﻤﺸﻜﻼﺕ ﺍﻟﺘﻤﺭﻴﻥ. 1ﻀﻊ ﺍﻟﻌﻼﻤﺔ \"ﺹ\" ﺃﻤﺎﻤﺎ ﻜل ﺠﻤﻠﺔ ﺼﺤﻴﺤﺔ ﻭ ﺍﻟﻌﻼﻤﺔ \"ﺥ\" ﺃﻤﺎﻤﺎ ﻜل ﺠﻤﻠﺔ ﺨﺎﻁﺌﺔ ﻤﻊ ﺍﻟﺘﻌﻠﻴل. lim f )(1 + h -f )(1 ∞= + -1ﺇﺫﺍ ﻜﺎﻨﺕ h→0 h ﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ fﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ . 1 C fﻟﺩﺍﻟﺔ ( )f ﺍﻟﺒﻴﺎﻥ ﻓﺈﻥ lim )f (h) - f (0 ﺇﺫﺍ ﻜﺎﻨﺕ = 0 : -2 h→0 h ﻴﻘﺒل ﻤﻤﺎﺴﺎ ﻴﻭﺍﺯﻱ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﺘﺭﺍﺘﻴﺏ . -3ﻜل ﺩﺍﻟﺔ ﻤﺴﺘﻤﺭﺓ ﻋﻨﺩ ﻋﺩﺩ x0ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ x0 )f ′(2 = 0 ﻓﺈﻥ lim f )( x = 4 : ﻜﺎﻨﺕ ﺇﺫﺍ -4 x→2 -5ﺇﺫﺍ ﻜﺎﻥ f ′ 2 = 0 :ﻓﺈﻥ ﺍﻟﻤﻤﺎﺱ ﻟﻤﻨﺤﻨﻰ ﺍﻟﺩﺍﻟﺔ fﻴﻭﺍﺯﻱ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﻔﻭﺍﺼل ﻓﻲ) ( ﺍﻟﻨﻘﻁﺔ ﺫﺍﺕ ﺍﻟﻔﺎﺼﻠﺔ .2 limﻏﻴﺭ ﻤﻭﺠﻭﺩ ﻓﺈﻥ ﺍﻟﺩﺍﻟﺔ f f )(-1 + h -f )( -1 ∞= + -6ﺇﺫﺍ ﻜﺎﻨﺕ h→0 h ﻏﻴﺭ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ . -1 -7ﻜل ﺩﺍﻟﺔ ﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ ﻤﺠﺎل ﻓﻬﻲ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻠﻰ ﻫﺫﺍ ﺍﻟﻤﺠﺎل. -8ﻜل ﺩﺍﻟﺔ ﺴﺎﻟﺒﺔ ﻋﻠﻰ ﻤﺠﺎل ﻫﻲ ﺩﺍﻟﺔ ﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﻫﺫﺍ ﺍﻟﻤﺠﺎل. f′ f -9ﻤﺸﺘﻘﺔ ﺍﻟﺩﺍﻟﺔ gﻫل ﺍﻟﺩﺍﻟﺔ g′ f (n) ( x ) = f ( x )n -10 -11ﺇﺫﺍ ﺍﻨﻌﺩﻤﺕ ﺍﻟﺩﺍﻟﺔ f ′′ﻋﻨﺩ x0ﻓﺈﻥ ﺍﻟﻨﻘﻁﺔ M x0 , f xﺍﻨﻌﻁﺎﻑ ﻟـ)) ( ( ) (Cf
limﻓﺈﻥ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ ﻟﻠﺩﺍﻟﺔ) ( ) (fh -f 0 -12ﺇﺫﺍ ﻜﺎﻨﺕ ∞= - >h h→0 fﻴﻘﺒل ﻨﺼﻑ ﻤﻤﺎﺱ ﻋﻨﺩ ﺍﻟﻨﻘﻁﺔ Oﻤﻥ ﺍﻟﻴﻤﻴﻥ ﻴﻭﺍﺯﻱ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﺘﺭﺍﺘﻴﺏ. limﻭ f )(2 + h -f )(2 =3 -13ﺇﺫﺍ ﻜﺎﻨﺕ > h→0 hﻴﻘﺒل ﻨﺼﻑ ﻤﻤﺎﺴﻴﻥ( ) ( ) ( ). Cf lim fﻓﺈﻥ 2+h - f 2 = -1 < h h→0=y x ﻫﻭ = y′ 1 -14ﺤل ﺍﻟﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ 2x ﻋﻠﻰ [∞]0 ; + -15ﺤل ﺍﻟﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ y′′ = cosx :ﻫﻭ y = cosxﻋﻠﻰ \ x 6ﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ ﻋﻠﻰ *\ . 1 -16ﺍﻟﺩﺍﻟﺔ x -17ﻟﺩﺭﺍﺴﺔ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﺩﺍﻟﺔ ﻋﻨﺩ ﻋﺩﺩ x0ﻨﺤﺴﺏ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ f ′ﺜﻡ ﻨﺤﺴﺏ ( ). f ′ x0 -18ﻜل ﺩﺍﻟﺔ ﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﻤﺠﺎل Iﻫﻲ ﺩﺍﻟﺔ ﻤﻭﺠﺒﺔ ﻋﻠﻰ I ﺍﻟﺘﻤﺭﻴﻥ. 2ﺃﺩﺭﺱ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ ﺍﻟﻌﺩﺩ x0ﻓﻲ ﻜل ﺤﺎﻟﺔ ﻤﻤﺎﻴﻠﻲ : f ( x) = x + 5 ; x0 = 1 (1 f ( x) = 3x + 10 ; x0 = 2 (2 f ( x) = cosx ; x0 = 0 (3 f ( x) = sin x ; x0 = π (4 6
)f (x = x2 - 4x + 2 ; x0 = 2 (5 x2 + x - 2 = )f (x x -2 ; x0 = 1 (6 x +3)7 )f (x = x2 + 9x - 2 ; x0 = 2 (7 x -1 ﺍﻟﺘﻤﺭﻴﻥ. 3ﺘﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ ( ). f x = 9 - x2 : (1ﻋﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺍﻟﺘﻌﺭﻴﻑ .f( ). f x ﺒﺎﻟﻨﺴﺒﺔ ﻟﻠﺩﺍﻟﺔ ﺍﻟﻘﻭل ﻤﺎﺫﺍ ﻴﻤﻜﻥ . lim x −3 (2ﺍﺤﺴﺏ : < x→3ﻤﺎﺫﺍ ﻴﻤﻜﻥ ﺍﻟﻘﻭل ﺒﺎﻟﻨﺴﺒﺔ ﺇﻟﻰ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ C fﻟﻠﺩﺍﻟﺔ ( ). f (3ﺒﻴﻥ ﺃﻥ C fﻫﻭ ﻨﺼﻑ ﺩﺍﺌﺭﺓ ( ). ﺍﻟﺘﻤﺭﻴﻥ. 4 fﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ ﻟﻠﻤﺘﻐﻴﺭ ﺍﻟﺤﻘﻴﻘﻲ xﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ : f ( x ) = 1 sin x ;x ≠ 0 x f (0) = 0 (1ﺃﺩﺭﺱ ﺍﺴﺘﻤﺭﺍﺭﻴﺔ ﺍﻟﺩﺍﻟﺔ fﻋﻨﺩ Oﺜﻡ ﻋﻠﻰ \ . (2ﺃﺩﺭﺱ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ Oﺜﻡ ﻋﻠﻰ \ . ﺍﻟﺘﻤﺭﻴﻥ. 5 ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﻜﻤﺎﻴﻠﻲ :
( ) ) f (x = x4 + 2x3 + x2 x2 + x + 1 )( x + 1 ; x ≠ -1 f )( −1 = + 1 3 -1ﻋﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ . f -2ﺍﺩﺭﺱ ﺍﺴﺘﻤﺭﺍﺭﻴﺔ ﺍﻟﺩﺍﻟﺔ fﻋﻨﺩ 0ﺜﻡ ﻋﻨﺩ . -1 -3ﺍﺩﺭﺱ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ 0ﺜﻡ ﻋﻨﺩ . -1 ﺍﻟﺘﻤﺭﻴﻥ. 6 ﺍﺤﺴﺏ ﺍﻟﺩﻭﺍل ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﻭﺍل ﺍﻟﻤﻌﺭﻓﺔ ﻜﻤﺎ ﻴﻠﻲ :f )( x = x +3 (2 ؛ = )f (x x2 - 4x+ 2 (1 )( x- 1) (x+ 2 x2+ x + 1 2 3 5 f ( =)x x 3 +4x +1 (4 ؛ f ( x)= (2x+1)2 .(x2 +3)2 (3 ؛ f ( x) = -4x2 + 5 x (6 f ( x)= - x2 +3x- 5 (5 x +1 f ( x)= - x2 + 8x -15 (7؛ f ( x)= - x+ 2 . x+ 5 (8 ﺍﻟﺘﻤﺭﻴﻥ. 7 ﻋﻴﻥ ﺍﻟﺩﻭﺍل ﺍﻟﻤﺸﺘﻘﺔ ﻟﻠﺩﻭﺍل ﺍﻟﻤﻌﺭﻓﺔ ﻜﻤﺎ ﻴﻠﻲ : ؛ f ( x) = ta3nx (2 f ( x) = cos3 x (1 )f (x = cos2x (4 ؛ f ( x) = sin x (3 1 - sin x 2 - sinx )f (x = 4 - cosx (6 =) f ( x؛ sin x- cos2x (5
ﺍﻟﺘﻤﺭﻴﻥ. 8 fﺩﺍﻟﺔ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻠﻰ \ ﻭ ﺍﺘﺠﺎﻩ ﺘﻐﻴﺭ ﺩﺍﻟﺘﻬﺎ ﺍﻟﻤﺸﺘﻘﺔ ﻤﻌﺭﻓﺔ ﻓﻲ ﺍﻟﺠﺩﻭل ﺍﻵﺘﻲ :∞x − -1 0 ∞2 3 +)f ′( x ∞+∞ + 00 2 -1 ﺍﺴﺘﻨﺘﺞ ﺍﺘﺠﺎﻩ ﺘﻐﻴﺭ ﺍﻟﺩﺍﻟﺔ . f ﺍﻟﺘﻤﺭﻴﻥ. 9 ﺇﻟﻴﻙ ﺍﻟﺘﻤﺜﻴﻠﻴﻴﻥ ﺍﻟﺒﻴﺎﻨﻴﻴﻥ ﺍﻵﺘﻴﻴﻥ C1و C2ﻋﻠﻰ ﺍﻟﻤﺠﺎل [ ] ( ) ( )-1 ; 1 ﻟﻠﺩﺍﻟﺘﻴﻥ f1ﻭ . f2 yy 22 11 -1 0 1x -1 0 1x -1 -1 )(C2 )(C1 -2 -2 -ﺒﻴﻥ ﺃﻨﻪ ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ xﻤﻥ ﺍﻟﻤﺠﺎل [ ]-1 ; 1 ﻓﺈﻥ f1′( x ) = f2 ( x ) : ﺍﻟﺘﻤﺭﻴﻥ. 10 ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺤﻴﺙ ( )f x = 1 + x : -1ﻋﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺍﻟﺘﻌﺭﻴﻑ. -2ﺍﺩﺭﺱ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ 0ﻟﻠﺩﺍﻟﺔ fﺜﻡ ﺍﻜﺘﺏ ﻤﻌﺎﺩﻟﺔ ﺍﻟﻤﻤﺎﺱ ﻟﻠﻤﻨﺤﻨﻲ C fﻋﻨﺩ ( ). O -3ﻋﻴﻥ ﺃﺤﺴﻥ ﺘﻘﺭﻴﺏ ﺘﺂﻟﻔﻲ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ . 0 -4ﺍﺤﺴﺏ ﻗﻴﻤﺔ ﻤﻘﺭﺒﺔ ﻟﻜل ﻤﻥ 1, 00007ﻭ 0,9999
-5ﺍﺩﺭﺱ ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ fﺜﻡ ﺃﻨﺸﺊ ( ). C f ﺍﻟﺘﻤﺭﻴﻥ. 11 ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺤﻴﺙ ( )f x = xn , n ∈ ` : -ﺍﺤﺴﺏ ﺍﻟﺩﻭﺍل ﺍﻟﻤﺸﺘﻘﺔ f (4) , f (3) , f ′′ , f ′ ﺍﻟﺘﻤﺭﻴﻥ. 12 fﺩﺍﻟﺔ ﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ f x = cos ax + b :ﺤﻴﺙ ( ) ( )a ≠ 0 :cos x+ π = - sin x aﻭ bﻋﺩﺩﺍﻥ ﺤﻘﻴﻘﻴﺎﻥ ﻨﻌﻠﻡ ﺃﻥ : 2 -ﺍﺤﺴﺏ ﻜل ﻤﻥ ) f ′( x ) , f ′′( x ) , f ′′′( xﺒﺩﻻﻟﺔ ﺠﻴﺏ ﺍﻟﺘﻤﺎﻡ . ﺍﻟﺘﻤﺭﻴﻥ. 13 y′′ +ﺜﻡ ﺍﺴﺘﻨﺘﺞ ﺍﻟﺤل ﺍﻟﺫﻱ 16π2 ﺤل ﺍﻟﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ y = 0 : 25 5 ﻴﺄﺨﺫ ﺍﻟﻘﻴﻤﺔ 1ﻋﻨﺩ 0ﻭ ﺩﺍﻟﺘﻪ ﺍﻟﻤﺸﺘﻘﺔ ﺘﻨﻌﺩﻡ ﻋﻨﺩ . 4 ﺍﻟﺘﻤﺭﻴﻥ. 14 ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺤﻴﺙ ( )f x = cos2 x : -1ﺒﻴﻥ ﺃﻨﻪ ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ ﺤﻘﻴﻘﻲ xﻓﺈﻥ ( ) ( )f ′′ x +4 f x - 2 = 0 -2ﺍﺴﺘﻨﺘﺞ ﺤﻼ ﻟﻠﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ y′′ = -4y + 2 : ﺍﻟﺘﻤﺭﻴﻥ. 15ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ ( )f x = x4 - 6x3 +12x2 +24x - 24 : -1ﺍﺤﺴﺏ ﺍﻟﻤﺸﺘﻘﺎﺕ ﺍﻟﻤﺘﺘﺎﺒﻌﺔ ﻟﻠﺩﺍﻟﺔ f ′, f ′′, f (3) , f (4) , f (5) : f ﻤﺎﺫﺍ ﺘﻼﺤﻅ ؟ -2ﺍﺩﺭﺱ ﺇﺸﺎﺭﺓ f ′′ xﺜﻡ ﺍﺴﺘﻨﺘﺞ ﻨﻘﻁ ﺍﻻﻨﻌﻁﺎﻑ ﻟﻠﻤﻨﺤﻨﻲ )( )(C ﺍﻟﻤﻤﺜل ﻟﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ . f
ﺍﻟﺘﻤﺭﻴﻥ. 16 ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺤﻴﺙ ( )f x = x x : -1ﺍﺩﺭﺱ ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ ، fﺜﻡ ﺃﻨﺸﺊ ﺒﺂﻟﺔ ﺒﻴﺎﻨﻴﺔ ﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ ). (C -2ﻋﻴﻥ ﺤﻼ ﻟﻠﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ 2 y′ - 3 x = 0 : ﺍﻟﺘﻤﺭﻴﻥ. 17ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺤﻴﺙ ( )f x = ax4 +bx3 + cx2 + 4 : ﺤﻴﺙ aﻭ bﻭ cﺃﻋﺩﺍﺩ ﺤﻘﻴﻘﻴﺔ . -ﻋﻴﻥ ﺍﻷﻋﺩﺍﺩ aﻭ bﻭ cﺘﻜﻭﻥ fﺤﻼ ﻟﻠﻤﻌﺎﺩﻟﺔ ﺍﻟﺘﻔﺎﻀﻠﻴﺔ : y′′ = 12x2 - 24x + 10 αﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ) ( ، )f (x = 1 ﺍﻟﺘﻤﺭﻴﻥ. 18 (1 + x)3 fﺩﺍﻟﺔ ﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ -1ﻋﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺍﻟﺘﻌﺭﻴﻑ ﻟﻠﺩﺍﻟﺔ . f -2ﺍﺩﺭﺱ ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ . f -3ﺍﻜﺘﺏ ﻤﻌﺩﻟﺔ ﺍﻟﻤﻤﺎﺱ ∆ ﻟﻠﻤﻨﺤﻨﻰ ℘ ﻋﻨﺩ ﺍﻟﻨﻘﻁﺔ ﺫﺍﺕ) ( ) ( 1 ﺍﻟﻔﺎﺼﻠﺔ ﺍﻟﻤﻌﺩﻭﻤﺔ .(0, 999)3 -4ﺃﻨﺸﺊ ﻜل ﻤﻥ ∆ ﻭ ℘ ﺒﻭﺍﺴﻁﺔ ﺁﻟﺔ ﺒﻴﺎﻨﻴﺔ ( ) ( ). -5ﻋﻴﻥ ﺃﺤﺴﻥ ﺘﻘﺭﻴﺏ ﺘﺂﻟﻑ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ . 0 1 -6ﺍﺤﺴﺏ ﺍﻟﻘﻴﻤﺔ ﺍﻟﻤﻘﺭﺒﺔ ﻟﻜل ﻤﻥ (1,001)3 :ﺜﻡ ﺍﻟﺘﻤﺭﻴﻥ. 19)f (x (x + 1)2 (Iﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ fﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ : x2 - 3x + 2 -1ﻋﻴﻥ D fﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ fﺜﻡ ﺒﻴﻥ ﺃﻨﻪ ﻤﻥ ﺃﺠل ﻜل ﻋﺩﺩ x
)f (x =a+ b + c ﻤﻥ D fﻓﺈﻥ : x -1 x -2 ﺤﻴﺙ aﻭ bﻭ cﺃﻋﺩﺍﺩ ﺤﻘﻴﻘﺔ ﻴﻁﻠﺏ ﺘﻌﻴﻴﻨﻬﺎ . -2ﺍﺩﺭﺱ ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ . f -3ﻋﻴﻥ ﺒﻭﺍﺴﻁﺔ ﻤﻌﺎﺩﻻﺘﻬﺎ ﺍﻟﻤﺴﺘﻘﻴﻤﺎﺕ ﺍﻟﻤﻘﺎﺭﺒﺔ ﻟﻠﻤﻨﺤﻨﻰ ) (Cﺍﻟﻤﻤﺜل ﻟﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ . f -ﺍﺩﺭﺱ ﺍﻟﻭﻀﻌﻴﺔ ﺍﻟﻨﺴﺒﻴﺔ ﻟﻠﻤﻨﺤﻨﻰ ) (Cﻭ ﺍﻟﻤﺴﺘﻘﻴﻡ ﺍﻟﻤﻘﺎﺭﺏ ﺍﻷﻓﻘﻲ ) ∆ ( . -4ﻋﻴﻥ ﺘﻘﺭﻴﺏ ﺘﺂﻟﻔﻲ ﻟﻠﺩﺍﻟﺔ fﻋﻨﺩ . 0 -5ﺃﻨﺸﺊ ). (C( )g x = x +2 x +1 (IIﻨﻌﺭﻑ ﺍﻟﺩﺍﻟﺔ gﻜﻤﺎ ﻴﻠﻲ : x2 - 3 x +2 -1ﻋﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ . g -2ﺍﻜﺘﺏ g xﺩﻭﻥ ﺭﻤﺯ ﺍﻟﻘﻴﻤﺔ ﺍﻟﻤﻁﻠﻘﺔ( ). -3ﺍﺩﺭﺱ ﺍﺴﺘﻤﺭﺍﺭﻴﺔ ﻭ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ gﻋﻨﺩ ﺍﻟﻌﺩﺩ . 0 -4ﺍﺩﺭﺱ ﺸﻔﻌﻴﺔ ﺍﻟﺩﺍﻟﺔ . g -5ﺍﺴﺘﻨﺘﺞ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ γﻟﻠﺩﺍﻟﺔ gﺍﻨﻁﻼﻗﺎ ﻤﻥ )( )(C -6ﻨﺎﻗﺵ ﺒﻴﺎﻨﻴﺎ ﻭﺠﻭﺩ ﻭﻋﺩﺩ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ (m -1) x2 - (3m +2) x + 2m -1 = 0ﺤﻴﺙ mﻭﺴﻴﻁ ﺤﻘﻴﻘﻲ. ﺍﻟﺘﻤﺭﻴﻥ. 20 ( )f x = (x - 2)2 fﺩﺍﻟﺔ ﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ : x2 - 1 GG) (Cﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ ﻓﻲ ﻤﻌﻠﻡ ﻤﺘﻌﺎﻤﺩ ﻭ ﻤﺘﺠﺎﻨﺱ ( )O ; i , j -1ﺍﺩﺭﺱ ﺘﻐﻴﺭﺍﺕ ﺍﻟﺩﺍﻟﺔ . f -ﺍﺩﺭﺱ ﺍﻟﻔﺭﻭﻉ ﺍﻟﻼﻨﻬﺎﺌﻴﺔ ﻭ ﺍﻟﻤﺴﺘﻘﻴﻤﺎﺕ ﺍﻟﻤﻘﺎﺭﺒﺔ .
-ﻋﻴﻥ ﺇﺤﺩﺍﺜﻴﺔ ﻨﻘﻁﺔ ﺘﻘﺎﻁﻊ ) (Cﻤﻊ ﺍﻟﻤﺴﺘﻘﻴﻡ ﺍﻟﻤﻘﺎﺭﺏ ﺍﻷﻓﻘﻲ ∆) ( -ﺃﻨﺸﺊ ﺍﻟﻤﻨﺤﻨﻰ ). (C -ﻨﺎﻗﺵ ﺒﻴﺎﻨﻴﺎ ﺤﺴﺏ ﻗﻴﻡ ﺍﻟﻌﺩﺩ ﺍﻟﺤﻘﻴﻘﻲ mﻋﺩﺩ ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ : (m - 1) x2 + 4x - m - 4 = 0= ( ) ( )g xx -2 2 -2ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ gﺍﻟﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ x2 - 1 : -ﺍﻜﺘﺏ g xﺩﻭﻥ ﺭﻤﺯ ﺍﻟﻘﻴﻤﺔ ﺍﻟﻤﻁﻠﻘﺔ ( ). -ﺍﺩﺭﺱ ﺍﺴﺘﻤﺭﺍﺭﻴﺔ ﻭ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ gﻋﻨﺩ . 0 -ﺒﻴﻥ ﺃﻥ g x = f xﻋﻠﻰ ﻤﺠﻤﻭﻋﺔ ﻴﻁﻠﺏ ﺘﻌﻴﻴﻨﻬﺎ ( ) ( ). -ﺍﺩﺭﺱ ﺸﻔﻌﻴﺔ ﺍﻟﺩﺍﻟﺔ . g -ﺍﺴﺘﻨﺘﺞ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ C′ﻟﻠﺩﺍﻟﺔ ( ). g ( )h x = (x - 2)2 -3ﻨﻌﺘﺒﺭ ﺍﻟﺩﺍﻟﺔ hﺤﻴﺙ : x2 - 1 -ﺍﻜﺘﺏ ﺍﻟﻌﺒﺎﺭﺓ h x :ﺒﺩﻻﻟﺔ ( ) ( ). f x -ﺍﺴﺘﻨﺘﺞ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ γﻟﻠﺩﺍﻟﺔ ( ). h( )ϕ x = (sin x - 2)2 -4ﻨﻌﺭﻑ ﺩﺍﻟﺔ ϕﺒﺎﻟﻌﺒﺎﺭﺓ : sin2 x - 1 -ﻋﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ . ϕ -ﺒﻴﻥ ﺃﻥ ϕﻫﻲ ﻤﺭﻜﺏ ﺩﺍﻟﺘﻴﻥ ﻴﻁﻠﺏ ﺘﻌﻴﻴﻨﻬﻤﺎ . -ﺍﺤﺴﺏ ﻤﺸﺘﻘﺔ ﺍﻟﺩﺍﻟﺔ . ϕ ﺍﻟﺘﻤﺭﻴﻥ. 21 f (1ﺩﺍﻟﺔ ﻋﺩﺩﻴﺔ ﻤﻌﺭﻓﺔ ﺒﺎﻟﻌﺒﺎﺭﺓ ( )f x = α + βx + γ :
ﺤﻴﺙ α , β , γﺃﻋﺩﺍﺩ ﺤﻘﻴﻘﻴﺔ Γﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ ( ). ﻋﻴﻥ α , β , γﺒﺤﻴﺙ ﺘﻜﻭﻥ ﺍﻟﻨﻘﻁﺘﺎﻥ Oﻭ A 1 ; -1ﻤﻥ ( ) ( )Γ ﻭ ﻴﻜﻭﻥ ﻤﻌﺎﻤل ﺘﻭﺠﻴﻪ ﺍﻟﻤﻤﺎﺱ ﻋﻨﺩ ﺍﻟﻨﻘﻁﺔ Oﻤﻥ Γﻤﺴﺎﻭﻴﺎ) ( -3 ﺇﻟﻰ . 4 g ( x) = -2 + 4 - 3x , x < 1 g (2ﺩﺍﻟﺔ ﻤﻌﺭﻓﺔ ﻜﻤﺎ ﻴﻠﻲ ( ) : g x = x -3+ x - 1 , x ≥ 1 ) (Cﺘﻤﺜﻴﻠﻬﺎ ﺍﻟﺒﻴﺎﻨﻲ . ﺃ -ﻋﻴﻥ ﻤﺠﻤﻭﻋﺔ ﺘﻌﺭﻴﻑ ﺍﻟﺩﺍﻟﺔ . g ﺏ -ﺍﺩﺭﺱ ﺍﺴﺘﻤﺭﺍﺭﻴﺔ ﻭ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻟﻠﺩﺍﻟﺔ gﻋﻨﺩ . 1 ﺠـ -ﺍﺩﺭﺱ ﺍﻟﻔﺭﻭﻉ ﺍﻟﻼﻨﻬﺎﺌﻴﺔ ﻭ ﺍﻟﻤﺴﺘﻘﻴﻤﺎﺕ ﺍﻟﻤﻘﺎﺭﺒﺔ ﻟﻠﻤﻨﺤﻨﻰ ). (C ﺩ -ﻋﻴﻥ ﻨﻘﻁ ﺘﻘﺎﻁﻊ ) (Cﻤﻊ ﺍﻟﻤﺴﺘﻘﻴﻡ ∆ ﺍﻟﺫﻱ ﻤﻌﺎﺩﻟﺘﻪ ( ). y = x : ﻫـ -ﺍﻜﺘﺏ ﻤﻌﺎﺩﻻﺕ ﺍﻟﻤﻤﺎﺴﺎﺕ ﻓﻲ ﻨﻘﻁ ﺘﻘﺎﻁﻊ ) (Cﻭ ∆ ( ). ﻭ -ﺃﻨﺸﺊ ﺍﻟﻤﻨﺤﻨﻰ ). (C
ﺍﻟﺤـﻠــــــﻭل ﺍﻟﺘﻤﺭﻴﻥ. 1 (1ﺨﺎﻁﺌﺔﺍﻟﺘﻌﻠﻴل :ﻨﻬﺎﻴﺔ ﺍﻟﻨﺴﺒﺔ ﻫﻲ ﺩﺭﺍﺴﺔ ﻗﺎﺒﻠﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ 1ﻭ ﺒﻤﺎ ﺃﻨﻬﺎ ﺘﺘﻨﺎﻫﻰ ﻨﺤﻭ ∞ +ﻓﺈﻥ fﻏﻴﺭ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ . 1 (2ﺨﺎﻁﺌﺔﺍﻟﻤﻤﺎﺱ ﻴﻭﺍﺯﻱ ﻤﺤﻭﺭ ﺍﻟﺘﺭﺍﺘﻴﺏ ﺇﺫﺍ ﻜﻨﺕ ﻨﻬﺎﻴﺔ ﺍﻟﻨﺴﺒﺔ ∞ +ﺃﻭ ∞ −ﻭﻋﻠﻴﻪ ﻓﺎﻟﻤﻤﺎﺱ ﻫﻨﺎﻙ ﻴﻭﺍﺯﻱ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﻔﻭﺍﺼل . (3ﺨﺎﻁﺌﺔﻓﻤﺜﻼ ﺍﻟﺩﺍﻟﺔ x 6 xﻤﺴﺘﻤﺭﺓ ﻋﻨﺩﻩ ﻟﻜﻨﻬﺎ ﻏﻴﺭ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ ﻋﻨﺩ .0 (4ﺨﺎﻁﺌﺔ( )2ﻋﻨﺩ ﺍﻻﺸﺘﻘﺎﻕ ﻗﺎﺒﻠﻴﺔ ﻭﻟﺩﺭﺍﺴﺔ 2 ﻋﻨﺩ ﻨﻬﺎﻴﺔ ﻤﺠﺭﺩ lim f x =4 x→2 lim )f (2 + h) - f (2 ﻨﺤﺴﺏ : h→0 h (5ﺼﺤﻴﺤﺔ ﻤﻴل ﺍﻟﻤﻤﺎﺱ ﻋﻨﺩ ﺍﻟﻨﻘﻁﺔ ﺫﺍﺕ ﺍﻟﻔﺎﺼﻠﺔ 2ﻴﺴﺎﻭﻱ 0ﻭ ﻤﻨﻪ ﺍﻟﻤﻤﺎﺱ ﻴﻭﺍﺯﻱ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﻔﻭﺍﺼل . (6ﺼﺤﻴﺤﺔ ﻷﻨﻪ ﺇﺫﺍ ﻜﺎﻨﺕ ﻨﻬﺎﻴﺔ ﺍﻟﻨﺴﺒﺔ ﻋﺩﺩ ﻓﺎﻟﺩﺍﻟﺔ ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ . (7ﺨﺎﻁﺌﺔﻓﺎﻟﺩﺍﻟﺔ x 6 xﻤﺴﺘﻤﺭﺓ ﻋﻠﻰ ∞ 0 ; +ﻟﻜﻨﻬﺎ ﻗﺎﺒﻠﺔ ﻟﻼﺸﺘﻘﺎﻕ[ [ ﻓﻘﻁ ﻋﻠﻰ ∞] [. 0 ; + (8ﺨﺎﻁﺌﺔﻓﺎﻟﺩﺍﻟﺔ x 6 x2ﺴﺎﻟﺒﺔ ﻋﻠﻰ \ ﻟﻜﻨﻬﺎ ﻏﻴﺭ ﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ ﻋﻠﻰ \
ﻓﻬﻲ ﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ -∞ ; 0ﻭ ﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ∞[ [ ] ]0 ; + (9ﺨﺎﻁﺌﺔ=h f ′h - g′h f ﻫﻲ ﺍﻟﺩﺍﻟﺔ hﺤﻴﺙ g2 ﻤﺸﺘﻘﺔ ﺍﻟﺩﺍﻟﺔ g (10ﺨﺎﻁﺌﺔﺍﻟﺭﻤﺯ ) f (nﻫﻭ ﺭﻤﺯ ﻟﻠﻤﺸﺘﻕ ﻤﻥ ﺍﻟﺭﺘﺒﺔ nﻟﻠﺩﺍﻟﺔ f n ، fﻫﻭ ﺭﻤﺯ ﻟﻠﺩﺍﻟﺔ ﻤﺭﻓﻭﻋﺔ ﻟﻸﺱ . n (11ﺨﺎﻁﺌﺔ ﺒل ﻴﺠﺏ ﺃﻥ ﺘﻐﻴﺭ f ′′ xﺇﺸﺎﺭﺘﻬﺎ ﻋﻨﺩ ( ). x0 (12ﺼﺤﻴﺤﺔﺒﻤﺎ ﺃﻥ ﻨﻬﺎﻴﺔ ﺍﻟﻨﺴﺒﺔ ﻫﻲ ∞ −ﻓﺈﻥ ﻤﻴل ﻨﺼﻑ ﺍﻟﻤﻤﺎﺱ ∞tanθ → -→ θﻭﻋﻠﻴﻪ ﻨﺼﻑ ﺍﻟﻤﻤﺎﺱ ﻴﻭﺍﺯﻱ ﺤﺎﻤل ﻤﺤﻭﺭ ﺍﻟﺘﺭﺍﺘﻴﺏ. -π ﻭﻤﻨﻪ 2 (13ﺼﺤﻴﺤﺔﻷﻥ ﺍﻟﺩﺍﻟﺔ fﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ 2ﻤﻥ ﺍﻟﻴﻤﻴﻥ ﻭ ﻋﺩﺩﻫﺎ ﺍﻟﻤﺸﺘﻕ ﻫﻭ 3ﻭﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ 2ﻤﻥ ﺍﻟﻴﺴﺎﺭ ﻭ ﻋﺩﺩﻫﺎ ﺍﻟﻤﺸﺘﻕ ﻫﻭ . -1ﻭ ﺒﻤﺎ ﺃﻥ ﺍﻟﻌﺩﺩﻴﻥ ﺍﻟﻤﺸﺘﻘﻴﻥ ﻏﻴﺭ ﻤﺘﺴﺎﻭﻴﻥ ﻓﺈﻥ ﺍﻟﺘﻤﺜﻴل ﺍﻟﺒﻴﺎﻨﻲ ﻴﻘﺒل ﻨﺼﻔﻲ ﻤﻤﺎﺴﻴﻥ .x 6 y′ = 1 = x 6 yﻫﻭ ﺍﻟﺩﺍﻟﺔ : (14ﺼﺤﻴﺤﺔ 2x ﻷﻥ ﻤﺸﺘﻘﺔ ﺍﻟﺩﺍﻟﺔ x ﻋﻠﻰ ]∞. ]0 ; + (15ﺨﺎﻁﺌﺔﻷﻥ y′ = -sin x :ﻭﻤﻨﻪ y′′ = -cosx : (16ﺨﺎﻁﺌﺔﺍﻟﺩﺍﻟﺔ ﻤﺘﻨﺎﻗﺼﺔ ﺘﻤﺎﻤﺎ ﻋﻠﻰ ﻜل ﻤﻥ ﺍﻟﻤﺠﺎﻟﻴﻥ -∞ ; 0ﻭ ∞] [ ] [0 ; + (17ﺨﺎﻁﺌﺔ
lim )f ( x + h) - f ( x ﺒل ﻨﺤﺴﺏ : h→0 h (18ﺨﺎﻁﺌﺔ ﺍﻟﺩﺍﻟﺔ x 6 2x : fﻤﺘﺯﺍﻴﺩﺓ ﺘﻤﺎﻤﺎ ﻋﻠﻰ \ ﻷﻥ ( )f ′ x > 0 : ﻟﻜﻥ ﺍﻟﺩﺍﻟﺔ fﻏﻴﺭ ﻤﻭﺠﺒﺔ ﻋﻠﻰ \ . ﺍﻟﺘﻤﺭﻴﻥ. 2 ﺩﺭﺍﺴﺔ ﻗﺎﺒﻠﻴﺔ ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ : x0 = )f (x x +5 ; x0 = 1 (1ﻟﺩﻴﻨﺎ : ﻭ ﻤﻨﻪ Df = [-5 ; +∞[ :؛ f (1) = 6lim f (1 + h)- f )(1 = lim 1+ h +5 - 6 hh→0 h h→0 = lim 6+h - ×6 6+h + 6 h→0 h 6+h + 6 = lim 6 +h - 6 h→0 h 6 + h + 6 = lim 1 =1=6 h→0 6 + h + 6 2 6 12 ( )f ′ 1 = 6 ﻭﻤﻨﻪ fﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩ 1ﺤﻴﺙ : 12 f ( x) = 3x + 10 ; x0 = 1 (2ﻟﺩﻴﻨﺎ : ﻭ ﻤﻨﻪ : f (2) = 4 ؛ Df = -10 ; ∞+ 3 lim f )(2 + h -f )(h = lim 3 (2 + h) +10 - 4 h→0h→0 h h
= lim 16 + 3h - 4 16 + 3h + 4 h→0 h× 16 + 3h + 4 = lim (16 + 3h) - 6 h→0 h 16 + 3h + 4 = lim 3 = 3 h→0 16 + 3h + 4 8 ( )f ′ 2 = 3 : ﺤﻴﺙ2 ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩf ﻭﻋﻠﻴﻪ 8 f ( x) = cosx ; x0 = 0 : ( ﻟﺩﻴﻨﺎ3 f (0) = 1 ؛Df = \ : ﻭ ﻤﻨﻪ f (h) - f (0) cos h - 1 1 - 2 sin2 h -1 h 2lim h = lim = lim h→0 hh→0 h→0 -2 sin2 h -sin2 h 2 2 = lim = lim h→0 h h→0 h h sin h 2 2 = lim -sin × lim h =0 h→0 h→0 2 f ( x) = sin x ; x0 = π : ( ﻟﺩﻴﻨﺎ4 6 f π = sin π = 1 ؛Df = \ : ﻭ ﻤﻨﻪ 6 6 2
f π +h - f π sin π +h - 1 6 6 6 2lim = lim h h→0 hh→0 sin π .cos h +cos π sin h - 1 6 6 2 = lim h→0 h 1 cos h + 3 sin h - 1 2 2 2 = lim h→0 h 1 (cos h - 1) + 3 sin h 2 2 = lim h→0 h 1 -2 sin2 h 3 sin h 2 2 = lim + h→0 h 2h sin2 h 2 = lim -1 + 3 sin h 2 2 h h→0 h 2 = 3 2 f (x) = x2 - 4x + 2 ; x0 = 2 : ( ﻟﺩﻴﻨﺎ5 x +x -2 : ﻭ ﻤﻨﻪ { }Df = x ∈ \ : x2 + x - 2 ≠ 0 -2 ، 1 : ﻫﻲx2 + x - 2 = 0 ﺤﻠﻭل ﺍﻟﻤﻌﺎﺩﻟﺔ
Df = \ - {-2 ; 1} : ﺇﺫﻥf (2) = (2)2 - 4 (2) + 2 = -2 = -1 (2)2 + 2 - 2 4 2 (2 + h)2 - 4 (2 + h) +2 + 1 2 = lim f (2 + h) - f (2) = lim (2 + h)2 - 4 (2 + h) -2 h→0 h h h→0 = lim 4+ 4h + h2 - 8 - 4h + 2 + 1 × 1 h→0 4+ 4h + h2 + 2+ h- 2 2 h = lim h2 h2 + 2 4 + 1 × 1 h→0 + 5h + 2 h h2 + 4+ h2 + 5h + 4 1 3h2 + 5h 2 h2 + 5h +4 h 2h h2 + 5h + 4 = lim × = lim h→0 ( ) ( )h→0 3h2 + 5h 5 2h h2 + 5h + 4 8 ( )= lim = h→0 ( ). f ′ 2 = 5 : ﺤﻴﺙ2 ﺘﻘﺒل ﺍﻻﺸﺘﻘﺎﻕ ﻋﻨﺩf ﺇﺫﻥ ﺍﻟﺩﺍﻟﺔ 8 f (x) = x -2 ; x =1 : ( ﻟﺩﻴﻨﺎ6 x +3 Df = { x ∈ \ / x + 3 ≠ 0 ﻭx ≥ 0} : ﻭ ﻤﻨﻪ Df = [0 ; +∞[ ; f (1) = -1 4 f (1+ h) - f (1) 1+ h -2 + 1 1+ h+ 3 4 lim h = lim h h→0 h→0
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