Found this in book

1. Oct 20, 2012

Jim Kata

prove

$$\sqrt[3]{26+15\sqrt{3}} = 2 + \sqrt{3}$$

and
$$\sqrt[3]{26-15\sqrt{3}} = 2 - \sqrt{3}$$

I am not sure how to do this

2. Oct 20, 2012

phinds

Uh, this is AWFULLY simple. What have you tried?

3. Oct 20, 2012

Jim Kata

to be honest I have no idea what to do

4. Oct 20, 2012

phinds

Well since one side is a cube root, how about you try cubing both sides.

5. Oct 20, 2012

Jim Kata

got it, yes extremely simple