If x-1/x= 3, then find the value of x^4+1/x^4 .

Correct option is C

Given:
x-1/x= 3
Formula Used:
x2 + 1/x2 = (x -1/x)2 + 2
Solution:
x-1/x= 3
On squaring both side
(x-1/x)^2= 3^2
x^2+1/x^2 -2x×1/x = 9
x^2+1/x^2 =11
On squaring both side
(x^2+1/x^2 )^1=11^2
x^4+1/x^4 +2x^2×1/x^2 = 121
x^4+1/x^4 =121 -2
x^4+1/x^4 =119