Question

Daca a+1/a=13 atunci a²+1/a² este : ?

Answer 1

[tex]a+\frac{1}{a}=13 |()^2\\ a^2+2\cdot a\cdot\frac{1}{a}+\frac{1}{a^2}=169\\ a^2+\frac{1}{a^2}+2=169\\ \boxed{a^2+\frac{1}{a^2}=167}[/tex]