How do I show $\displaystyle sqrt(2/5)$ as an exact value?
Thanks
That is an exact value.
$\displaystyle \sqrt{\frac{2}{5}} = \frac{\sqrt2}{\sqrt5}$
You can rationalise the denominator by multiplying by $\displaystyle \frac{\sqrt5}{\sqrt5}$
$\displaystyle \frac{\sqrt2}{\sqrt5} \cdot \frac{\sqrt5}{\sqrt5} = \frac{\sqrt{10}}{5}$
Although it's no more exact than the original expression