# Math Help - Pre-Calc

1. ## Pre-Calc

Sorry i dont know how to do the signs...

Thank you.

2. Originally Posted by ep78

Sorry i dont know how to do the signs...

Thank you.
from the unit circle (with which you should be familiar) ...

$\cos\left(\frac{\pi}{4}\right) = \cos\left(\frac{5\pi}{4}\right) = \frac{\sqrt{2}}{2}$

so ... $3x + \pi =$ ?