Question

if x+1/x = 5 then find x^2 - 1/x^2​

Answer 1

Answer:

x^2 - 1/x^2 = (x+1/x)(x-1/x) ......(1)

(x-1/x)^2 = (x+1/x)^2 - 4 = 5^2 - 4 = 21

(x - 1/x) = √21

Substitute the values of x+1/x and x-1/x in (1)

5×√21 = 5√21 is Answer