# pi/12

• March 25th 2011, 01:26 AM
JazKW347
pi/12
how can i use the difference identity to find pi/12, because i keep getting 0 when i try it.
• March 25th 2011, 01:29 AM
Prove It
Are you sure you're not trying to find $\displaystyle \sin{\frac{\pi}{12}}$ or $\displaystyle \cos{\frac{\pi}{12}}$?
• March 25th 2011, 01:32 AM
JazKW347
Ii is Cos(pi/12) i guess i looked at it wrong, i did not see the Cosine
• March 25th 2011, 01:44 AM
Prove It
Either evaluate $\displaystyle \cos{\left(\frac{\pi}{3} - \frac{\pi}{4}\right)}$ using the angle difference identity, or evaluate $\displaystyle \cos{\left(\frac{1}{2}\cdot \frac{\pi}{6}\right)}$ using the half angle identity.