Question

If x4 +1/x4 =623 , then x+1/x =

Answer 1

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

x^2 + 1/x^2 = 25

(x+1/x)^2 - 2 = 25

(x+1/x)^2 = 27

x+1/x = 3√7

Answer 2

(×4+1/×4)/(×+1/×) you will get answer