What is the period and amplitude for y=3 cos x?

Sep 21, 2015

The period is $1$ and the amplitude is $3$.

Explanation:

For a general cosine function of the form $Y = A \cos \left(B x\right)$, $A$ is the amplitude (The maximum absolute value of the oscillation) and $B$ is the period (meaning that the function completes one cycle every $\frac{2 \pi}{B}$ interval).

This function has the amplitude $3$, giving an oscillation between $- 3$ and $3$, and the period $1$, giving the interval length of $2 \pi$.

Graphed, it looks like this:

graph{y = 3cosx [-10, 10, -5, 5]}