Question

if x-1/x =5, find the value of x²+1/x²​

Answer 1

Answer:

Given : $x-1/5 =5$

To find : $x^2+ \frac{1}{x^2}$

Solution :

$(x-\frac{1}{x})^2=5^2\\x^2 -2+ \frac{1}{x^2} =25 \\\x^2+\frac{1}{x^2} = 27$

Answer 2

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