x^2+y^2-4x-2y+5=0,则log2(1/5)=

问题描述:

x^2+y^2-4x-2y+5=0,则log2(1/5)=
错了,是则logx(y)^x的值时

x^2+y^2-4x-2y+5=0
( x-2)^2+(y-1)^2=0
x=2y=1
logx(y)^x=log2(1)=0