1. ## How is this radical being reduced?

Hi all,

I'm going through a application for learning maths and I've hit a confusing point, unfortunately it fails to depart with any information on workings out of a problem.

The app informs me that:

$\displaystyle x = \frac{4 \pm \sqrt{20}}{2}}$

Reduces to this:

$\displaystyle x = {2 \pm \sqrt{5}}$

I have no idea how that radical is being divide by the whole number, basically I need to know how I would make this:

$\displaystyle \frac{\sqrt{20}}{2}}$

Reduce to this:

$\displaystyle \sqrt{5}$

2. $\displaystyle \displaystyle \frac{\sqrt{20}}{2}} = \frac{\sqrt{4\times 5}}{2}}=\frac{\sqrt{4}\sqrt{ 5}}{2}} = \frac{2\sqrt{ 5}}{2}} = \sqrt{ 5}$

3. That's Fantastic! Thanks

4. Originally Posted by code
That's Fantastic! Thanks
No, that's pickslides !

5. Fantastic is off solving much more advanced problems.

6. Originally Posted by DrSteve
Fantastic is off solving much more advanced problems.
Maybe it's relative?

7. Don't forget the alternative...(as it could be dangerous to have "picks" agree with you)

$\displaystyle \displaystyle\frac{\sqrt{20}}{2}=\frac{\sqrt{20}}{ \sqrt{4}}=\sqrt{\frac{20}{4}}$

8. FANTASTIC Archibald!