If $x^4 + (\frac{1}{x^4}) = 322,$ then what is the value of $x^3 - (\frac{1}{x^3})$ ? |
16 76 96 46 |
76 |
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 $x^4 + (\frac{1}{x^4}) = 322,$ then x2 + \(\frac{1}{x^2}\) = \(\sqrt {322 + 2}\) = 18 and x - \(\frac{1}{x}\) = \(\sqrt {18 - 2}\) = 4 If x - \(\frac{1}{x}\) = n then, $x^3 - \frac{1}{x^3}$ = 43 + 3 × 4 = 76 |