Question

if x^2-1/x^2=8,the value of x^4+1/x^4 is​

Answer 1

${x}^{2} - \frac{1}{ {x}^{2} } = 8 \\ \\ ( { {x}^{2} - \frac{1}{ {x}^{2} } })^{2} = 64 \\ \\ {x}^{4} + \frac{1}{ {x}^{4} } - 2 = 64 \\ \\ {x}^{4} + \frac{1}{ {x}^{4} } = 66$