If x+1x=12, find the value of x−1x.
x+1x=12Squaring on both sides,(x+1x)2=(12)2⇒ x2+1x2+2×x2×1x2=144⇒ x2+1x2=144−2=142Now (x−1x)2=x2+1x2−2=142−2=140=4×35∴ x−1x=±√4×35=± 2√35