If x4 + \(\frac{1}{x^4}\) = 49727, the positive value of ( x + \(\frac{1}{x}\) -15 ) is? |
15 14 0 10 |
0 |
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 + \(\frac{1}{x^4}\) = 49727 x2 + \(\frac{1}{x^2}\) = \(\sqrt {49727 + 2}\) = 223 So, ( x + \(\frac{1}{x}\) - 15 ) = ( \(\sqrt {223 + 2}\) - 15 ) = 0 |