## mitchelsewbaran Group Title Which of the following is an exact value of cos 15° ? one year ago one year ago

1. mitchelsewbaran Group Title

2. Azteck Group Title

$\large \cos15=\cos(60-45)$ Double angle results. $\large\cos(60-45)=\cos60\cos45+\sin60\sin45$

3. Azteck Group Title

Now find out for cos15 after I gave you a headstart