If $x^4 + \frac{1}{x^4}=14159$, Then a Possible value of $ x + \frac{1}{x}$is :

69 121 81 11

11

If x4 + \(\frac{1}{x^4}\) = a then x2 + \(\frac{1}{x^2}\) = \(\sqrt {a + 2}\) = b and x + \(\frac{1}{x}\) = \(\sqrt {b + 2}\) If $x^4 + \frac{1}{x^4}=14159$ then x2 + \(\frac{1}{x^2}\) = \(\sqrt {14159 + 2}\) = 119 and x + \(\frac{1}{x}\) = \(\sqrt {119 + 2}\) = 11