Practicing Success
If x - \(\frac{1}{x}\) = 2\(\sqrt{15}\) then find the value of ( x + \(\frac{1}{x}\) )3 |
512 216 343 729 |
512 |
⇒ If x - \(\frac{1}{x}\) = a then x + \(\frac{1}{x}\) = \(\sqrt {a^2 + 4}\) Here, x - \(\frac{1}{x}\) = 2\(\sqrt{15}\), then ⇒ x + \(\frac{1}{x}\) = \(\sqrt {(2\sqrt{15})^2 + 4}\) = 8 ⇒ ( x + \(\frac{1}{x}\) )3 = 83 = 512 |