设x^4-xy+y^4=1,求y''在点(0,1)处的值
设xy>0,且xy=4x+y+12,求xy的最小值
设曲线y=y(x),在其上点(x,y)处的切线斜率为2xy,并且过点(0,1),求该曲线的方程
设x>=0,y>=0,且x+2y=1/2,求函数log1/2(8xy+4y^2+1)的最值
设|X-2|+(Y+1/4)^2=0,试求代数式X^2(X^2-XY+Y)-X(X^3-2X^2Y+XY-1)
若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
x-y=1,xy=2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知|3-y|+|x+y|=0,求[2(x+y)-3(xy+4)]÷1/xy的值.
设|X-2|+(Y+1/4)^2=0,试求代数式X^2(X^2-XY+Y)-X(X^3-2X^2Y+XY-1)的值.
Y的平方+4Y+4+根号X+Y-1=0求XY的值
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?