Find the phase shift of the function.
-$$y = - 3 \cos ( 4 x + \pi )$$
A) $3 \pi$ units to the right
B) $\frac { \pi } { 4 }$ units to the left
C) $4 \pi$ units to the right
D) $\frac { \pi } { 3 }$ units to the left

Question

Quizplus · Accepted Answer

The phase shift of a trigonometric function in the form $y = a \cos(bx + c)$ or $y = a \sin(bx + c)$ is calculated as $-\frac{c}{b}$. For the given function $y = -3\cos(4x + \pi)$, $b = 4$ and $c = \pi$, so the phase shift is $-\frac{\pi}{4}$ units, which means the graph is shifted $\frac{\pi}{4}$ units to the left.

Find the Phase Shift of the Function y=−3cos⁡(4x+π)y = - 3 \cos ( 4 x + \pi )y=−3cos(4x+π)

Find the Phase Shift of the Function $y = - 3 \cos ( 4 x + \pi )$