Thread: Hi, having problems with a complex number multiplication

Hi everyone, I'm Joanne and currently studying to become a maths teacher (1 year in to studying).


I'm having problems trying to work out the below multiplication.




I've worked out that the polar form of (2-2i)^12 is ( sorry about the ?'s)

But I am unsure of what to do next.

Do I work out the polar form of , then multiply them together, or am I doing this wrong to begin with?


Thanks

Originally Posted by Jojo55

Hi everyone, I'm Joanne and currently studying to become a maths teacher (1 year in to studying).
I'm having problems trying to work out the below multiplication.

I've worked out that the polar form of (2-2i)^12 is ( sorry about the ?'s)

.

thus .

But .

Can you finish?

Are you familiar with the Binomial Theorem?

Study this link: Binomial Theorem

Originally Posted by jpritch422

Are you familiar with the Binomial Theorem?

Study this link: Binomial Theorem

What does that have to do with the OP?

Originally Posted by Plato

What does that have to do with the OP?

I think jpritch is suggesting that the problem be done without DeMoivre/Polar form.
I disagree with that suggestion, but I'm fairly certain that's where he's going with that.

Originally Posted by Henderson

I think jpritch is suggesting that the problem be done without DeMoivre/Polar form.
I disagree with that suggestion, but I'm fairly certain that's where he's going with that.

Actually, I understood what the post meant. I want to see why jpritch422 wanted to use that.

The irony is that DeMoivre's Rule is used for many proofs about binomial coefficients.

Originally Posted by Plato

.

thus .

But .

Can you finish?

Sorry for the late reply. I managed to solve to get the answer of -1

Thanks for the help on this