## Trending News

Promoted

# homework help trig please!?

give answers to these calculations in trigonometric form:

(a) 12(cos(65degree)=isin(65degree)) / 9(cos(24degree)+isin(24degree))

(b) 2(cos(pi/6)+isin(pi/6))x 4(cos(pi/3)+isin(pi/3))

### 1 Answer

Relevance

- az_lenderLv 78 years agoFavorite Answer
I'll start with (b):

2(cos(pi/6) + isin(pi/6)) = 2e^(i pi/6)

and

4(cos(pi/3) + isin(pi/3)) = 4e^(i pi/3)

When you multiply them together you get

8e^(ipi/6+i pi/3) = 8e^(i pi/2)

= 8(cos(pi/2) + i sin(pi/2)) = 8(0+i) = 8i.

My problem with (a) is that I think the "=" sign is supposed to be a plus sign. (???)

Then you have

12 e^(13 i pi/36) / 9 e^(2 i pi/15)...the exponents will be subtracted...

= (4/3) e^(41 i pi/180)

= (4/3) ( cos(41 degrees) + i sin(41 degrees) )

Still have questions? Get your answers by asking now.