Question

qual e raiz quadrada de 8 sobre raiz quadrada de 5

Answer 1

Racionalizando: $\dfrac{\sqrt{8}}{\sqrt{5}}=\dfrac{\sqrt{8}\cdot\sqrt{5}}{\sqrt{5}\cdot\sqrt{5}}=\dfrac{\sqrt{40}}{\sqrt{25}}=\dfrac{\sqrt{40}}{5}}$. Fatorando $40$ em primos, obtemos $40=2^3\times5$. Assim, $\dfrac{\sqrt{40}}{5}=\dfrac {\sqrt{2^3\times5}}{5}=\dfrac{2\sqrt{10}}{5}$.