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)

下面代码的输出结果是（）。 x=17 y=4[br][/br] print(divmod(x,y)) A: 1, 4 B: (4, 1) C: 4, 1 D: (1, 4)

下列程序的运行结果是（）。Publicclasssun{Publicstaticvoidmain(Stringargs&#91;&#93;){intx=4，y=0；if(Math．pow(X，2)==16)y—x；if(Math．pow(X，2)<15)y—l／x；if(Math．pow(X，2)>15)y=(int)Math．pow(X，2)+1；system．out．println(y)；}} A: 4 B: 17 C: 18 D: 0．25

已知随机变量X, Y的方差D(X)=4,，D(Y)=9，协方差Cov(X,Y)=2，则D(2X-Y)= A: 25 B: 13 C: 17 D: 21

设有如下程序： public class Sun { public static void main(String args&#91; &#93;) { int x,y; x=4; y=0; if(Math.pow(x,2)==16) y=x; if(Math.pow(x,2)<15) y=1/x; if(Math.pow(x,2)＞15) y=(int)Math.pow(x,2)+1; System.out.println(y); } } 程序的运行结果是( )。 A: 4 B: 17 C: 18 D: 0.25

如下C程序的输出是什么？#include &#91;stdio.h&#93;void Func1 (int x, int y);void Func2 (int *x, int *y); int main() { int x = 3; int y = 4;Func1 (x, y); printf ("x = %d, y = %d\n", x, y);Func2(&x, &y); printf ("x = %d, y = %d\n", x, y);} void Func1 (int x, int y) { x = x + y; y = x - y; x = x - y; printf ("x = %d, y = %d\n", x, y);} void Func2 (int *x, int *y) { *x = *x + *y; *y = *x - *y; *x = *x - *y;;} A: x = 3, y = 4x = 3, y = 4x = 3, y = 4 B: x = 4, y = 3x = 4, y = 3x = 4, y = 3 C: x = 3, y = 4x = 3, y = 4x = 4, y = 3 D: x = 4, y = 3x = 3, y = 4x = 4, y = 3

int x,y;x=17;y=26;printf(%d,y/=(x%=6));程序段的运行结果是

由直线x=1/2,x=2,曲线y=1/x以及x轴所围成图形的面积为() A: 15/4 B: 17/4 C: D: 2ln2

假设x=4,y=5,下列哪个逻辑表达式是真的? A: !(x==4)^y!=5 B: x!=4^y==5 C: x==5^y==4 D: x!=5^y!=4

x=9,y=4,x%y=______ ,x//y=______