Question

已知X²+Y²-10X-2Y+26=0,求X²Y²方的算术平方根.

Answer 1

x²+y²-10x-2y+26=0

x²-10x+25+y²-2y+1=0

(x-5)²+(y-1)²=0

x-5=0 x=5

y-1=0 y=1

√(x²y²)=|xy|=|5|=5