设=cos4x，则dy= A: 4sin4xdx B: -4sin4xdx C: (1/4)sin4xdx D: -(1/4)sin4xdx

已知\( y = \tan x \)，则\( dy \)为（ ）. A: \( \tan xdx \) B: \( \cos xdx \) C: \( {\sec ^2}xdx \) D: \( \sin xdx \)

已知\( y = \cos x \)，则\( dy \)为（ ）. A: \( \cos x \) B: \( {\rm{ - }}\sin x \) C: \( \cos xdx \) D: \( {\rm{ - }}\sin xdx \)

sinα-cosα=m求sin^4α+cos^4α的值

$\int \sin^3 x \cos x dx = $ A: $\frac{\sin^4 x}{4} +C$ B: ${\sin^4 x} +C$ C: $\frac{\cos^4 x}{4} +C$ D: $\frac{\cos^4 x}{4} +C$

设$\int_0^\pi {[f(x) + f''(x)]\sin xdx = 5} $，$f(\pi ) = 2$，求$f(0)$=（ ） A: 1 B: 2 C: 3 D: 4

函数\(y = \cos (4 - 3x)\)的导数为（ ）. A: \( - 3\sin \left( {4 - 3x} \right)\) B: \(3\sin \left( {4 - 3x} \right)\) C: \(3\sin \left( {4 + 3x} \right)\) D: \( - 3\sin \left( {4 + 3x} \right)\)

（1-sin^6α-cos^6α）/（sin^2α-sin^4α）的值

\(\int_{\rm{1}}^{\rm{4}} {xdx} = \)( )。 A: 7 B: 7.5 C: 8 D: 8.5

求微分方程[img=143x21]17da5f14490e50e.png[/img]的通解,实验命令为(). A: dsolve(D2y-2*Dy+5*y=sin(2*x),x)ans =exp(x)*sin(2*x)*C2+exp(x)*cos(2*x)*C1+1/17*sin(2*x)+4/17*cos(2*x) B: dsolve('D2y-2*Dy+5*y=sin(2*x)','x')ans =cos(2*x)*(sin(4*x)/17 - cos(4*x)/68 + 1/4) - sin(2*x)*(cos(4*x)/17 + sin(4*x)/68) + C1*cos(2*x)*exp(x) - C2*sin(2*x)*exp(x) C: dsolve(D2y-2*Dy+5*y=sin(2*x),'x','y')ans =exp(x)*sin(2*x)*C2+exp(x)*cos(2*x)*C1+1/17*sin(2*x)+4/17*cos(2*x)