If (x2+1x2=7) , find x−1x
±√(5)
Given
(x2+1x2=7)
x−1x
Squaring we get
(x−1x)2 = x2+1x2−2 (Using (a+b)2)
= (7−2)
= 5
Taking Square root on both sides , we get
(x−1x) = ±√(5)