已经z1=x+y+(x^2-xy-2y)i,z2=(2x-y)-(y-xy)i,问x,y取什么时候实数值时(1)z1,z2都是实数?(2)z1,z2互为共轭复数?

已经z1=x+y+(x^2-xy-2y)i,z2=(2x-y)-(y-xy)i,问x,y取什么时候实数值时(1)z1,z2都是实数?(2)z1,z2互为共轭复数? 已知复数z1=(2x+1)+i,z2=y+(2-y)i 若z1=z2,且x属于R,y为纯虚数,求z f(xy,x-y)=x^2+y^2+xy;f(x,y)/∂x;f(x,y)/∂y x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? matlab把两个三维图形画在一个图中,这样编程哪错了 [x,y]=meshgrid(-2:0.1:2); >> z1=x.*x-2*y.*y; >> z2代码如下[x,y]=meshgrid(-2:0.1:2);z1=x.*x-2*y.*y;z2=1;hold on,mesh(x,y,z1),mesh(x,y,z2),hold off (-x-y)(x^2+xy+y^2) 化简x^-y^/x^-2xy+y^ 2*(x-y)²(y-x)(xy) （x^2+xy/x-y)/（xy/x-y)计算 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? (-x+2y)(2x+y)-(2x+y)(y-2x)-3xy=?因式分解 f(x+y,x-y)=(x^2-y^2)/2xy,求f(x,y)! x+y=-3 xy+x+y=-2 x/y+y/x=? 正数x,y满足x-y=2xy,求x-y/x+y的值. f(x+y,x-y)=2xy(x-y),求f(x,y) x^2+xy+x=36,y^2+xy+y=20,求x+y. 若x^2+xy+y=14,y^2+xy+x=28,求x+y 函数f(xy,x+y)=x^2+xy+y^2,则df(x,y)=?