Question

If x+1/x = √7. Find x^2 + 1/ x^2​

Answer 1

$x \: - \: \frac{1}{x} = \: \sqrt{7}$

$On \: \: squaring \: \: both \: \: sides, \: \: we \: \: get -$

${x}^{2} \: + \: \frac{1}{ {x}^{2} } \: - 2 \: = \: 7$

$or, \: {x}^{2} \: + \: \frac{1}{ {x}^{2} } \: = \: 7 \: + \: 2$

$→ \: {x}^{2} \: + \: \frac{1}{ {x}^{2} } \: = \:9$