If x4+\(\frac{1}{{x}^{4}}\) = 1442    x > 0 find x-\(\frac{1}{x}\)

7 8 6 15

6

x4+\(\frac{1}{{x}^{4}}\) = 1442 x2+\(\frac{1}{{x}^{2}}\) = \(\sqrt {1442+2}\) = 38 x-\(\frac{1}{x}\) = \(\sqrt {38-2}\) = 6 x-\(\frac{1}{x}\) = 6