y=x+√(1-x2) y2=x2+(1-x2)+2x√(1-x2)
已知实数x.y满足(x2+y2)(x2+y2-1)=2,求x2+y2的值
已知圆x2+y2-2x-2y+1=0求x2+y2的最大值
x(x-1)-(x2-y)=-3,求x2-y2-2xy的值
x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
已知x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
2010.09.已知x、y为实数,且(x2+y2)(x2+y2+1)=20,求x2+y2的值
已知x-y+1,X2+Y2=25 求(x+y)2和x2-xy+y2的值
先化简再求值2(x2-xy)-3(2x2-3xy)-2[x2-(2x2-xy+y2)],其中x=-1,y=-2.
求圆x2+y2+2x-6y+1=0与圆x2+y2+2y-..
已知实数x、y满足(x2+y2)(x2+y2-1)=2,则x2+y2的值为______.
已知圆x2+y2-2x-2y+1=0求 x2+y2的最大值 x2为x的平方
先化简,再求值:(1)2x2-5x x2 4x,其中x=-3 (2)(3x2-xy-2y2)-2(x2 xy-2y2),