Question

help needed with the 3rd part only

Answer 1

http://screencast.com/t/UusQdDiRv

Answer 2

@AccessDenied

Answer 3

It seems you ended up in the Chemistry section... was it just a mistake or was there an issue putting it in Math?

Answer 4

If you did part ii, we should have a graph of 1+2i and 1-3i like this:

I believe we are looking at the fact that:
tan^-1 (2/1) = theta and tan^-1 (3/1) = phi. The whole angle between 1+2i and 1-3i is then theta + phi.