I explained how to use the power rule on Page 1 of this thread, but it's just a rule you can follow on terms of a function that involve a power in order to find the derivative. You'll probably talk more about it in class, but if you want to know more, just Google it.

As for where the 2 ends up, constants become 0 when you differentiate them. Think of it like this -

2 = 2*x^(0) --> 2*0*x^(-1) = 0

This post was edited by SexualNinja on Oct 7 2013 08:23pm

So any term that isn't to a power doesn't exist in that rule?

Correct. Here's another way (that's also more correct) to think about it.

f(x) = 2.
We all know that graph is simply a flat line.
Since the derivative is the slope of the original equation, and the original equation is a flat line, the slope, and therefore the derivative, are clearly 0.

in the video he uses delta x... but sometimes people use h instead (like we did above), its the same quantity, just a different name for it.

This post was edited by Azrad on Oct 7 2013 08:53pm