Question

If x-1/x = √5, find the value of x^2+1/x^2​

Answer 1

Step-by-step explanation:

$x {}^{2} + \frac{1}{x {}^{2} } \\ = (x — \frac{1}{x} ) {}^{2} + 2 \times x \times \frac{1}{x} \\ = ( \sqrt{5} ) {}^{2} + 2 \\ = 5 + 2 = 7$