设函数f(x,y)= xy^2/(x^2+y^2); (x2+y2)≠ 0 ; (x2+y2)=0 问 :
若X2+Y2-2X-6Y+10=0 ,求(x2-y2)/xy的值
已知x2+4y2+x2y2-6xy+1=0,求 x4-y4/2x-y 乘 2xy-y2/xy-y2 除以(x2+y2/x
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
求函数f(x,y)=(x2+y2)2-2(x2-y2)的极值
已知X2+Y2+8X+6Y+25=0 求代数式X2++XY+4Y2分之X2-4Y2 减X+2Y分之X的值
X2+Y2+8X+6Y+25=0 求代数式(x2-4y2/x2+4xy+4y2)-x/x+2y
若x<y<0,则x2−2xy+y2+x2+2xy+y2=( )
已知X2-2x+y2+6y+10=0,求(x2-2xy)/(xy+y2)的值
已知x、y是实数且满足x2+xy+y2-2=0,设M=x2-xy+y2,则M的取值范围是______.
已知非零实数x,y满足:x2+xy-2y2=0,求(x2+3y+y2)/(x2+y2)的值
已知x2+y2-10x-6y+34=0,求(x-y/x+y)2÷x2-y2/xy×x2+2xy+y2/x2-xy 的值.
已知xy满足x2+y2-6x+2y+10=0,求立方根号x2-y2的值