Simplify the following A) (cosx - isinx)^5 B) (sinx - icosx)^4 for A i get cos5x - isin5x I think this is right...? not sure if B is done the same or not. any help?
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Hello, Originally Posted by djmccabie Simplify the following A) (cosx - isinx)^5 B) (sinx - icosx)^4 for A i get cos5x - isin5x I think this is right...? not sure if B is done the same or not. any help? Here is what you can do De Moivre's formula says : Remember that the sine function is odd and the cosine function is even. So
so did i do it right :S is it different when cosine and sine are switched round? thanks
Originally Posted by djmccabie so did i do it right :S is it different when cosine and sine are switched round? thanks Yes, it's the correct result. If they're switched... do you mean ? Then it's just
hi thanks for helping me. its actualyy (sinx - icosx) does this change things??
Originally Posted by djmccabie hi thanks for helping me. its actualyy (sinx - icosx) does this change things?? Yes : Multiply and divide by i : So
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