How do you write the following complex number in rectangular form?

5(cos((5pi)/4)+isin((5pi)/4))

1 Answer
May 21, 2018

(-5sqrt2)/2-(5sqrt2)/2i

Explanation:

5(cos((5pi)/4)+isin((5pi)/4))

Distribute:
5*cos((5pi)/4)+5*isin((5pi)/4)

Recall unit circle coordinates:
5*-sqrt2/2+5*-sqrt2/2i=

(-5sqrt2)/2-(5sqrt2)/2i