# How do you graph f(x)=Cos( x + pi/4 ) ?

Nov 14, 2016

See explanation.

#### Explanation:

$\text{Amplitude} = 1$

$\text{Period} = \frac{2 \pi}{b} = \frac{{360}^{\circ}}{b}$

$\frac{{360}^{\circ}}{1} = {360}^{\circ} \text{/cycle}$

$\text{Phase Shift} = - \frac{b}{c}$

$- \frac{\pi}{4} \cdot \frac{1}{1} = - {45}^{\circ}$ phase shift

Make a list of points for every ${30}^{\circ}$, like $\frac{\pi}{6}$, $\frac{\pi}{3}$, $\frac{\pi}{2}$, until you reach ${360}^{\circ}$. Plot these points as you normally would for reference and then adjust each point ${45}^{\circ}$ to the left.

A negative phase shift you'll move the plotted points to the left a positive phase shift adjusts the plotted points to the right.