已知\( y = f({x^2}) \),假设\( f(u) \)二阶可导,则\( y'' \)为( ).
A: \( 4{x^2}f''({x^2}){\rm{ + }}2f'({x^2}) \)
B: \( {x^2}f''({x^2}){\rm{ + }}2f'({x^2}) \)
C: \( 4{x^2}f''({x^2}){\rm{ + }}f'({x^2}) \)
D: \( {x^2}f''({x^2}){\rm{ + }}f'({x^2}) \)
A: \( 4{x^2}f''({x^2}){\rm{ + }}2f'({x^2}) \)
B: \( {x^2}f''({x^2}){\rm{ + }}2f'({x^2}) \)
C: \( 4{x^2}f''({x^2}){\rm{ + }}f'({x^2}) \)
D: \( {x^2}f''({x^2}){\rm{ + }}f'({x^2}) \)
举一反三
- 已知\( y = {f^2}(x) \),假设\( f(u) \)二阶可导,则 \( y'' \)为( ). A: \( 2{[f'(x)]^2} + 2f(x)f'(x) \) B: \( 2[f'(x)] + 2f(x)f''(x) \) C: \( 2{[f'(x)]^2} + 2f(x)f''(x) \) D: \( 2{[f'(x)]^2} + f(x)f''(x) \)
- 若函数$f(x)$具有二阶导数,且$y=f({{x}^{2}})$,则$y'' =$( )。 A: $f'' ({{x}^{2}})$ B: $2f'’ ({{x}^{2}})$ C: $2f’ ({{x}^{2}})+4{{x}^{2}}f’' ({{x}^{2}})$ D: $4{{x}^{2}}f’ ({{x}^{2}})+2f'' ({{x}^{2}})$
- 设\( f(x) \)的一个原函数为\( F(x) \),则\( \int {f(2x)dx} = \)( ) A: \( F(2x) + {\rm{ }}C \) B: \( {1 \over 2}F(2x) + {\rm{ }}C \) C: \( F({x \over 2}) + {\rm{ }}C \) D: \( 2F({x \over 2}) + {\rm{ }}C \)
- 【单选题】对任意实数x 1 , y 1 , x 2 , y 2 , x 1 < x 2 , y 1 < y 2 , 分布函数P{x 1 <X≤x 2 , y 1 <Y≤y 2 }=? A. F(x 2 , y 2 )+ F(x 1 , y 1 )+ F(x 1 , y 2 )+ F(x 2 , y 1 ) B. F(x 2 , y 2 )- F(x 1 , y 1 )+ F(x 1 , y 2 )- F(x 2 , y 1 ) C. F(x 2 , y 2 )+ F(x 1 , y 1 )- F(x 1 , y 2 )- F(x 2 , y 1 ) D. F(x 2 , y 2 )- F(x 1 , y 1 )- F(x 1 , y 2 )+ F(x 2 , y 1 )
- 【单选题】设 f ( x ) 是可导函数, 则 lim Δ x → 0 f 2 ( x + △ x ) − f 2 ( x ) △ x = ()。 A. [ f ′ ( x ) ] 2 " role="presentation"> [ f ′ ( x ) ] 2 B. 2 f ′ ( x ) " role="presentation"> 2 f ′ ( x ) C. 2 f ( x ) f ′ ( x ) " role="presentation"> 2 f ( x ) f ′ ( x ) " role="presentation"> 2 f ( x ) f ′ ( x ) x ) 2 f ( x ) f ′ ( x ) " role="presentation"> f ( x ) f ′ ( x ) D. 不存在;