Practicing Success
If x - \(\frac{1}{x}\) = 2\(\sqrt{2}\) then find the value of x2 - \(\frac{1}{x^2}\). |
2\(\sqrt{2}\) 3\(\sqrt{6}\) 4\(\sqrt{3}\) 4\(\sqrt{2}\) |
4\(\sqrt{3}\) |
⇒ If x - \(\frac{1}{x}\) = a then x + \(\frac{1}{x}\) = \(\sqrt {a^2 + 4}\) Here, x - \(\frac{1}{x}\) =2\(\sqrt{2}\), then ⇒ x + \(\frac{1}{x}\) = \(\sqrt {(2\sqrt{2})^2 + 4}\) = 2\(\sqrt{3}\) Formula → x2 - y2 = (x + y) (x - y) ⇒ x2 - \(\frac{1}{x^2}\) = (x + \(\frac{1}{x}\)) (x - \(\frac{1}{x}\)) = 2\(\sqrt {3}\) × 2\(\sqrt{2}\) = 4\(\sqrt{6}\) |