Without graphing the function, determine its amplitude or period as requested.
-$y = - 4 \cos \frac { 1 } { 3 } x \quad$ Find the amplitude.
A) $\frac { 4 \pi } { 3 }$
B) 4
C) $\frac { \pi } { 4 }$
D) $6 \pi$

Question

Quizplus · Accepted Answer

The amplitude of a trigonometric function like $y = -4\cos\left(\frac{1}{3}x\right)$ is given by the absolute value of the coefficient in front of the cosine function, which in this case is $|-4| = 4$.

Without Graphing the Function, Determine Its Amplitude or Period as Requested