- #1

MiddleEast

- 23

- 5

- Homework Statement
- Derive sum to product formulas using Euler formula

- Relevant Equations
- Euler formula e^ix = cos x + i sin x

Hello,

This is actually not homework.

I was google searching for "proving trig identities from geometric point of view), found one of the result which proves trig identities using Euler formula. I really liked it. Easier, quicker & simple.

But when the author speak about sum to product formulas, he gave unclear hint and did not do the derivation. Please see attached.

Can some1 explain how to do it using Euler? am really struggling with memorizing sum to product identities.

Thanks

This is actually not homework.

I was google searching for "proving trig identities from geometric point of view), found one of the result which proves trig identities using Euler formula. I really liked it. Easier, quicker & simple.

But when the author speak about sum to product formulas, he gave unclear hint and did not do the derivation. Please see attached.

Can some1 explain how to do it using Euler? am really struggling with memorizing sum to product identities.

__I still can derive them easily from angles sum & difference sin(x+y) ... etc, But I want to know how to do it using Euler formula.__Thanks