Question

if X plus one by x equals 6 then a^4 +1/a^4 equals

Answer 1

We have x + 1/x = 6

squaring both sides (x +1/x)^2 = 6^2

   By using formula (a+b)^2 = a^2 + 2ab + b^2

       x^2 + 1/x^2 + 2 x.1/x = 36

        x^2 + 1/x^2 = 34

Squaring again (x^2 + 1/x^2)^2 = (34)^2

  a^4 + 1/a^4 + 2 x a^2 x 1/a^2 = 1156

        a^4 + 1/a^4 + 2 = 1156

  or a^4 + 1/a^4 = 1156 - 2 = 1154