How to calculate
If you already know the formulas forfor , 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.
That is both interesting and very useful!
Thanks for sharing this, JaneFairFax!
That it can be extended to any power makes it all the more interesting!
It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.
Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.