If x^4 - 12x^2 + 1 = 0 , then what will be the value of x^4 + 1/(x^4)

We know that,

If $K+\frac{1}{K}=n$

then, $K^2+\frac{1}{K^2}$ = n² – 2

If $x^4 - 12x^2 + 1 = 0 $,

Divide by x² on the both sides of equation we get,

x² + \(\frac{1}{x^2}\) = 12

then the value of $x^4 + \frac{1}{x^4}$ = 12² – 2 = 142