Question

If x=3+
$\sqrt{8}$
then find the value of x + 1/x​

Answer 1

$x = 3 + \sqrt{8} \\ \frac{1}{x} = \frac{1}{3 + \sqrt{8} } \\ \frac{1}{x} = \frac{1}{3 + \sqrt{8} } \times \frac{3 - \sqrt{8} }{3 - \sqrt{8} } \\ \frac{1}{x} = \frac{3 - \sqrt{8} }{9 - 8} \\ \frac{1}{x} = 3 - \sqrt{8} \\ \\ x + \frac{1}{x} = 3 + \sqrt{8} + 3 - \sqrt{8} = 6$