x²+y²-8x-10y+41=0,求x/y-y/x的值.
问题描述：
x²+y²-8x-10y+41=0,求x/y-y/x的值.
答
x²+y²-8x-10y+41=0
（x²-8x+16）+（y²-10y+25）=0
（x-4）²+（y-5）²=0
x-4=0 y-5=0
x=4 y=5
x/y-y/x
=4/5-5/4
= -9/20
答
x²+y²-8x-10y+41=0
(x-4)²+（y-5)²=0
所以
x=4,y=5
x/y-y/x
=4/5-5/4
=-9/20