If x4 + \(\frac{1}{x^4}\) = 82367, the positive value of x + \(\frac{1}{x}\) is? |
17 19 13 15 |
17 |
If x4 + \(\frac{1}{x^4}\) = a then x2 + \(\frac{1}{x^2}\) = \(\sqrt {a + 2}\) = b and x + \(\frac{1}{x}\) = \(\sqrt {b + 2}\) ATQ, x4 + \(\frac{1}{x^4}\) = 82367 x2 + \(\frac{1}{x^2}\) = \(\sqrt {82367 + 2}\) = 287 So, x + \(\frac{1}{x}\) = \(\sqrt {287 + 2}\) = 17 |