A. plotyy(y1,y2)
B. plotyy(x1,y1)
C. plotyy(x1,y1,x2,y2)
D. plotyy(x1,x2)
37.已知x_{n)},y_{n)}满足:x_(1)=y_(1)=(1)/(2),x_(n+1)=sin x_(n),y_(n+1)=y_(n)^2(n=1,2
,X_(9) 与 Y_(1),Y_(2), ... ,Y_(9) 是分别来自动体X,Y的简单样本,统计量 W= (X_(1)+X_(2)+ ... +X_(9)
2.设X与Y相互独立且都服从N(0,3²)分布,X_(1),X_(2),...,X_(9),Y_(1),Y_(2),...,Y_(9)分别是来自 于X和Y的样本
已知(x_(1),y_(1)),(x_(2),y_(2))是函数y=2^x的图象上两个不同的点,则( )A. $log_2\frac{y_1+y_2}{2}<
1.17 二次型 f(x_(1),x_(2))=x_(1)^2-2x_(2)^2+4x_(1)x_(2)bigcirc y_(1)^2-2y_(2)^2bigc
X_(9)是来自总体X的样本,Y_(1),Y_(2),... Y_(9)是来自总体Y的样本,则统计量U=(X_(1)+...+X_(9))/(sqrt(Y_(1
已知x_(1)[k]=-1,1,0,2,1,0,-1,x_(2)[k]=1,2,3,-1,-1,-1,-1,画出下列离散序列的波形。(1) y_(1)[k]=x
【5.18】若可逆线性变换x=Py可将二次型f(x_(1),x_(2))=x_(1)^2+2x_(2)^2+2x_(1)x_(2)化为规范形y_(1)^2+y_
函数z=f(x,y)在P(x_(0),y_(0))处一定有f_(xy)(x_(0),y_(0))=f_(yx)(x_(0),y_(0)).A 对B 错A. 对B
3.设X_(1),...,X_(10)为来自标准正态总体Xsim N(0,1),Y_(1)=7sum_(i=1)^3X_(i)^2,Y_(2)=3sum_(i=