If x+1x=11, find the value of x2+1x2.
x+1x=11
Squaring both sides,
(x+1x)=(11)2⇒ x2+1x2+2=121⇒ x2+1x2=121−2=119∴ x2+1x2=119
If x−1x=−1, find the value of x2+1x2.