- #1

- 140

- 0

is there another way of solving the problem above besides using the multiple angles formula?

- Thread starter ProBasket
- Start date

- #1

- 140

- 0

is there another way of solving the problem above besides using the multiple angles formula?

- #2

- 609

- 0

use this identity:

[tex]

sin u = \frac{e^{iu}-e^{-iu}}{2i}

[/tex]

edit:

expand the sine in term of exponential, multiply them and regroup them into 2 cosine, then do the integral

[tex]

sin u = \frac{e^{iu}-e^{-iu}}{2i}

[/tex]

edit:

expand the sine in term of exponential, multiply them and regroup them into 2 cosine, then do the integral

Last edited:

- #3

- 140

- 0

- #4

ehild

Homework Helper

- 15,543

- 1,909

useProBasket said:

is there another way of solving the problem above besides using the multiple angles formula?

[tex] \sin{\alpha}\sin{\beta} = \frac{\cos(\alpha-\beta) - \cos(\alpha + \beta)}{2}[/tex]

ehild

- #5

- 609

- 0

I can eye ball the answer using my way......

the answer is....

1/14 sin7x - 1/50 sin25x

the expansion of the complex number is easy.... there are only 4 terms

- Last Post

- Replies
- 15

- Views
- 1K

- Last Post

- Replies
- 4

- Views
- 2K

- Last Post

- Replies
- 1

- Views
- 1K

- Last Post

- Replies
- 4

- Views
- 4K

- Last Post

- Replies
- 4

- Views
- 10K