Question

If x-1/x=√5 , find the value of x²-1/x²​

Answer 1

Step-by-step explanation:

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