How would I simplify this expression:

(1/2)cos(x/2)cosx+sinxsin(x/2)

I can't find the identity to simplify.

Printable View

- Oct 15th 2012, 05:45 PMMajMinorMore trig simplification
How would I simplify this expression:

(1/2)cos(x/2)cosx+sinxsin(x/2)

I can't find the identity to simplify. - Oct 15th 2012, 05:55 PMMarkFLRe: More trig simplification
Is it:

$\displaystyle \frac{1}{2}\left(\cos\left(\frac{x}{2} \right)\cos(x)+\sin(x)\sin\left(\frac{x}{2} \right) \right)$ ? - Oct 15th 2012, 05:58 PMMajMinorRe: More trig simplification
No, it's:

(1/2)[cos(x/2)cosx]+sinxsin(x/2) - Oct 15th 2012, 06:07 PMMarkFLRe: More trig simplification
Okay, I just wanted to be sure. I would look at product-to-sum identities.