Practicing Success
If 2x2 + 5x + 1 = 0, then find the value of \(\frac{1}{3}\) (x - \(\frac{1}{2x}\)). |
\(\frac{\sqrt {17}}{4}\) \(\frac{\sqrt {17}}{6}\) \(\frac{\sqrt {14}}{3}\) \(\frac{\sqrt {17}}{2}\) |
\(\frac{\sqrt {17}}{6}\) |
2x2 + 5x + 1 = 0 divide by 2x x + \(\frac{5}{2}\) + \(\frac{1}{2x}\) = 0 x + \(\frac{1}{2x}\) = -\(\frac{5}{2}\) x - \(\frac{1}{2x}\) = \(\sqrt {(-\frac{5}{2})^2 - \frac{4}{2}}\) = \(\sqrt {\frac{17}{4}}\) Now, \(\frac{1}{3}\) (x - \(\frac{1}{2x}\)) = \(\frac{\sqrt {17}}{3 × 2}\) = \(\frac{\sqrt {17}}{6}\) |