• 2022-06-07
    求函数 y=tan2(1+2x2)的微分:
    A: 8x×tan(1-2x2)×sec2(1+2x2)dx .
    B: 8x×tan(1+2x2)×sec2(1+2x2)dx .
    C: -8x×tan(1+2x2)×sec2(1+2x2)dx .
    D: 8x×tan(1+2x2)×sec2(1-2x2)dx .
  • B

    内容

    • 0

      $\int {{{x\cos x} \over {{{\sin }^3}x}}} dx = \left( {} \right)$ A: $ - {x \over {2{{\sin }^2}x}} - {1 \over 2}\tan x + C$ B: $ - {x \over {2{{\sin }^2}x}} - {1 \over 2}\cot x + C$ C: $ - {x \over {2{{\cos }^2}x}} - {1 \over 2}\cot x + C$ D: $ - {x \over {2{{\cos }^2}x}} - {1 \over 2}\tan x + C$

    • 1

      求函数[img=173x42]17da65390bf2806.png[/img]的导数; ( ) A: tan(pi/4 + x/2) B: (tan(pi/4 + x/2)^2/2 ) /tan(pi/4 ) C: (tan(pi/4 + x/2)^2/2 + 1/2) D: (tan(pi/4 + x/2)^2/2 + 1/2) /tan(pi/4 + x/2)

    • 2

      若\( \int {f(x)dx = {x^2} + C} \),则\( \int {xf(1 - {x^2})dx = } \)( ) A: \( 2{(1 - {x^2})^2} + C \) B: \( - {1 \over 2}{(1 - {x^2})^2} + C \) C: \( {1 \over 2}{(1 - {x^2})^2} + C \) D: \( - 2{(1 - {x^2})^2} + C \)

    • 3

      【单选题】设X为连续型随机变量, 其概率密度: f(x)=Ax2, x∈(0,2); 其它为0. 求(1)A=(); (2) 分布函数F(x)=(); (3) P{1<X<2} (10.0分) A. (1)3/8; (2)x<0,    F(x)=0; 0≤x<2, F(x)=1/8x³; x≥2,  F(x)=1; (3) 7/8 B. (1)5/8; (2)x<0,    F(x)=0; 0≤x<2,   F(x)=1/8x³; x≥2,    F(x)=0 (3) 1/8

    • 4

      不定积分$\int<br/>\tan ^{2}x \sec^{2}x\text{d}x=$( ) A: $\frac{1}{3}{{\tan }^{3}}x+C$ B: $-\frac{1}{3}{{\tan }^{3}}x+C$ C: $\frac{1}{3}{{\sec }^{3}}x+C$ D: $-\frac{1}{3}{{\sec }^{3}}x+C$