若根号(a²-5a+1)+根号(b²-4b+4)=0,求(a²+1/a²)·b的值

问题描述:

若根号(a²-5a+1)+根号(b²-4b+4)=0,求(a²+1/a²)·b的值

根号(a²-5a+1)+根号(b²-4b+4)=0
a²-5a+1=0,b²-4b+4=0
a-5+1/a=0,b=2
a+1/a=5
(a²+1/a²)·b
=[(a+1/a)^2-2]*b
=23*2
=46