Multiplication of complex exponential numbers

(625e^(3.46i))*(4.4e^(1.22i))

when i multiply it out i get 2750e^(4.2212i) From there I'm supposed to make it into polar and rectangular forms. the answers in the book are 2750(cos268.1 degrees + i*sin268.1 degrees) for polar form and -89.1 -2750i for rectangular form. Both my answers were incorrect according to the book. So my multiplication must have been off, if anyone can check it for me please.

Quote:

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Originally Posted by OzzMan

(625e^(3.46i))*(4.4e^(1.22i))

when i multiply it out i get 2750e^(4.2212i) From there I'm supposed to make it into polar and rectangular forms. the answers in the book are 2750(cos268.1 degrees + i*sin268.1 degrees) for polar form and -89.1 -2750i for rectangular form. Both my answers were incorrect according to the book. So my multiplication must have been off, if anyone can check it for me please.

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First not , so you should have: since:



and radian is degrees (rounded to that precission).

Of course you should also know that:



RonL

woops i multiplied exponents.