Question

find the value of x squared minus 1 by 5 at X equal to -1​

Answer 1

Answer:

Given :

( x + 1 /x ) = 5

We need to find x2 + 1 / x2

( x + 1 / x )2 = 25

= x2 + 1 / x2 + 2 (x)(1/x) = 25

= x2 + 1/x2 + 2 = 25

= x2 + 1 / x2 = 25 – 2

= x2 + 1 / x2=23

Hence x2  + 1 / x2 = 23