Question

Trục căn thức ở mẫu :

\(\frac{1}{\sqrt{2}+\sqrt{3}}\)

Answer 1

\(\frac{1}{\sqrt{2}+\sqrt{3}}\\ =\frac{\sqrt{3}-\sqrt{2}}{\left(\sqrt{3}+\sqrt{2}\right)\left(\sqrt{3}-\sqrt{2}\right)}\\ =\frac{\sqrt{3}-\sqrt{2}}{\left(\sqrt{3}\right)^2-\left(\sqrt{2}\right)^2}\\ =\frac{\sqrt{3}-\sqrt{2}}{1}=\sqrt{3}-\sqrt{2}\)

Answer 2

\(\frac{1}{\sqrt{2}+\sqrt{3}}=\frac{\sqrt{2}-\sqrt{3}}{\left(\sqrt{2}+\sqrt{3}\right)\left(\sqrt{2}-\sqrt{3}\right)}=\frac{\sqrt{2}-\sqrt{3}}{\left(\sqrt{2}\right)^2-\left(\sqrt{3}\right)^2}=\frac{\sqrt{2}-\sqrt{3}}{2-3}=\frac{\sqrt{2}-\sqrt{3}}{-1}=-\left(\sqrt{2}-\sqrt{3}\right)=-\sqrt{2}+\sqrt{3}\)