Question

Como resolve isso?

(√2 - 1)²

Answer 1

Lembrete:

⇒ $\left(a+b\right)^2=a^2+2ab+b^2$
⇒ $\left(a-b\right)^2=a^2-2ab+b^2$
------------------------------------------------------------
$\left(\sqrt{2}-1\right)^2\\\left(\sqrt{2}\right)^2-\left(2\cdot \sqrt{2}\cdot 1\right)+1^2\\2-2\sqrt{2}+1\\\boxed{\bold{3-2\sqrt{2}}}$