Question

If x+1/x = 4, find the value of x4 + 1/x4

Answer 1

x + 1/x = 4 -> ( x + 1/x)2 = 16 -> x2 + 1/x2 + 2 = 16 -> x2 +1/x2 = 14

Now,

x2 + 1/x2 = 14 -> ( x2 + 1/x2)2 = 196 → x4 + 1/x4 + 2 = 196 -> x4 +1/x4 = 194