## mitchelsewbaran 2 years ago Which of the following is an exact value of cos 15° ?

1. mitchelsewbaran

2. Azteck

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

3. Azteck

Now find out for cos15 after I gave you a headstart