This is a thread for complex number problems in applied mathematics.

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- Nov 3rd 2013, 07:41 AManil86Complex Numbers
This is a thread for complex number problems in applied mathematics.

You can see attachment for the question. - Nov 3rd 2013, 03:40 PMSlipEternalRe: Complex Numbers
What help do you need? What do you have so far? For the first one, I would start with multiplying out by and see what you get (consider the sum or difference of angles formula for cosine).

For the second problem, again, I would start with the difference of angles formula for cosine. - Nov 4th 2013, 01:28 AManil86Re: Complex Numbers
Thanks for your time.

I tried that but can't get the solution. Can you solve & illustrate it to me? - Nov 4th 2013, 01:41 AMSlipEternalRe: Complex Numbers
Show your work and we can help you figure out where you are going wrong. To type in your answer, use [tex] tags around any mathematics.

- Nov 20th 2013, 01:46 AManil86Re: Complex Numbers
Thanks for replies. I got the solution.

- Nov 20th 2013, 01:51 AManil86Re: Complex Numbers
Solve equations using De Moivre's theorem:

1. x^7 + x^4 + x^3 + 1 = 0

2. x^7 - x^4 + x^3 - 1 = 0

I tried multiplying with (x - 1). Also tried putting x^3 = y; didn't work. - Nov 20th 2013, 04:41 AMtopsquarkRe: Complex Numbers
Please put new questions in a new thread.

-Dan