Question

Please help!I know it's probably simple, but I don't understand...

Answer 1

For the reciprocal, you swap numerator and denominator.

a. The reciprocal of $\frac{\sqrt{2}}{2}$ is $\frac{2}{\sqrt{2}}$
To rationalize the irrational denominator, multiply numerator and denominator by the radical, then simplify.
$=\frac{2 \times \sqrt{2}}{\sqrt{2} \times \sqrt{2}} = \frac{2 \sqrt{2}}{2} = \sqrt{2}$

b. $\frac{-2}{\sqrt{3}} = \frac{-2 \sqrt{3}}{3}$