若x^2-4x+4+y^2-2/3y+2/9=0求x+1/y及x^2+1/y^2的值
问题描述:
若x^2-4x+4+y^2-2/3y+2/9=0求x+1/y及x^2+1/y^2的值
答
由x^2-4x+4+y^2-2/3y+1/9=0,得,
(x^2-4x+4)+(y^2-2/3y+1/9)=0,
(x-2)^2+(y-1/3)^2=0,
∴x=2,y=1/3
∴x+1/y
=2+3
=5
x^2+1/y^2
=4+9
=13