√(X-1) + (Y+2)^2 = 0

|2x+y+1|+√2y+3x=0则x.y= 设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于 求下列式子dy/dx (1) x^2y-x+y=0；(2) x√y =y-1 若|x+2y-1|+y²+4y+4=0,求（2x-y）²-2（2x-y)(x+2y)+(x+2y)& 已知x,y满足约束条件：x-y+1>=0,x+y-2>=0,x 若|x+y-1|+（x-y-2)²=0,求代数式（x+2y)(x-2y）-（2x-y)(-y-2x)的值. 微分方程y''=3√y,x=0,y=1,y'=2 2x²+1/2y²-2x-3y+5=0,求(2x√9x-y²√x/y³)-(√1 已知（x-2）+√y-x+1=0,求x+y的平方根 已知(2x+1)*2+y*2+2y+1=0 求{(x*2+y*2)-(x-y)*2+2y(x-y)}/(2y) y=ln(x+√x^2+1),求y y=1-x^2 x>=0 ,y=sin|x|/x x