Question

Ajutor,va rog!Calculati $x^{2} + \frac{1}{ x^{2} }$,stiind ca $x- \frac{1}{x} =3$

Answer 1

(x - 1/x)^2 = x^2 - 2 + 1/x^2 = 9

x^2 + 1/x^2 = 11