Question

x^2+1/x^2 = 7,then x - 1/x^2= ?


(lol I already know the answer,this question is simply to test your knowledge)​

Answer 1

( x - 1/x )² = x² + 1/x² - 2

= 7 - 2 = 5

x - 1/x = √ 5... 1

( x + 1/x ) ² = 9

x + 1/x = 3.... 2

x² - 1/x² = x + 1/x * x - 1 /x = 9√5 Answer