Thanks for sharing this, JaneFairFax!

That it can be extended to any power makes it all the more interesting! ]]>

If you already know the formulas for

for , then you can calculate using the following trick:You expand the LHS and use the formulas you already know.

For example, the following formulas should be familiar to most people:

You can then apply the above trick to prove that

And with that, you can go on and find

. And so on, and so forth. ]]>