Question

已知4x+9y-4x-6y+2=0,求[√y/√（√x+√y）]-[√y/√（√x-√y）]的值求大神帮助

Answer 1

[√y/√（√x+√y）]-[√y/√（√x-√y）]=-2y/(x-y) 4(x-1/2)^2+9(y-1/3)^2=0 得x=1/2,y=1/3 于是原式=-2/3/(1/2-1/3)=-4