If you saw the first one (a LONG time ago), then you should know the pattern:

If you saw the first one (a LONG time ago), then you should know the pattern:

                   $i=\sqrt{-1}$

                   $i^2=-1$

                   $i^3=-i$

                   $i^4=1$​

Now, try to solve this:

          $i^{2016}+i^{2015}+i^{2014}...+i^2+i$

This is actually much easier than it looks.

          $36i$

This is requires you to use the technique:

          $i^{20162015}$

A little non-imaginary question:

In factoring, can't you just use 2-1 for everything?

Example: Factor x+1   SOLUTION: (x+1)(2-1)? LOL I don't think so (don't get me wrong: I know very well that you cannot use 1 in factoring)

GOOD LUCK AND MAY THE MATHS BE EVER IN YOUR FAVOR