Complex Numbers : Addition, Subtraction and Multiplication : ExamSolutions

[Mal1234567]

I'm sorry to say I am completely unfamiliar with binomial expansion. It looks as if a lot more multiplication was required using that method.For me (4) simply boiled down to (5-12i)^2 which then easily resolved to the same answer.

[ExamSolutions]

@Mal1234567 Yes I can appreciate that when it is to the power of 4 it may be reasonably quick to expand the brackets the way you suggest but sooner or later the Binomial Expansion will be required. Suppose you had to expand (3-2i)^10 say, your way would become very long. That was really the point behind me doing the binomial expansion. I should have made it clearer.