1. Prove.....yeah right :(

I am having a brain freeze on this one. Solution would be great.

Prove:

sin330cos150 - cos390sin390 = 0

Thanks so much

2. Evaluate

$\sin(330)\cos(150) - \cos(390)\sin(390)$

If it is equal to zero then you have proved it.

I'll kick it off

$\sin(330)\cos(150) - \cos(390)\sin(390)$

$\sin(360-30)\cos(180-30) - \cos(360+30)\sin(360+30)$

$-\sin(30)\times -\cos(30) - \cos(30)\sin(30)$

you have it from here?