[题目]设 approx N(0,1), 令 =-x-2, 则 Y~ ()-|||-
+2y)dx+(2x+3(y)^2)dy在整个xoy平面内是某一函数+2y)dx+(2x+3(y)^2)dy的全微分,则+2y)dx+(2x+3(y)^2)dy
设X~N(1, 2), Y~N(-1, 3),且X与Y相互独立,则2X-Y~( )A. N(3, 8)B. N(3, 5)C. N(3, 11)D. N(3,2
【题目】设y=y(x)是由方程 xy+e^y=x+1 确定的隐函数,则(d^2y)/(dx^2)|_(x=0)=【题目】设y=y(x)是由方程 xy+e^y=x
设X、Y相互独立,X~N(-1,2),Y~N(1,3),则X+2Y服从( )A. N(1,8)B. N(1,14)C. N(1,22)D. N(1,40)
设随机变量 X ~N ( 0 , 1 ) , Y = 2 X - 2 则 A Y ~ N ( -2 , 1 ) B Y ~ N ( -1 , 4 )
设 X ~N (-1,2), Y ~N (1,3), X与Y相互独立则 X-2Y服从( )A. N(1,14)B. N(-3,14)C. N(0,5)D. N(
设 f(x) = (x)/(2x+3),则 f^(n)(0) = ________。设 $f(x) = \frac{x}{2x+3}$,则 $f^{(n)}(0
设 f(x) = (x)/(2x+3),则 f^(n)(0) = ____________。设 $f(x) = \frac{x}{2x+3}$,则 $f^{(n
设函数 y=y(x) 由方程 ^3+x(y)^2+(x)^2y+6=0 确定,设函数 y=y(x) 由方程 ^3+x(y)^2+(x)^2y+6=0 确定,