# How do you find the period and amplitude of y=-3sin(x/3)?

Jun 20, 2018

As below.

#### Explanation:

$y = A \sin \left(B x - C\right) + D$

$y = - 3 \sin \left(\frac{x}{3}\right)$

A = -3, B = 1/3), C = D = 0

$\text{Amplitude } = | A | = | - 3 | = 3$

$\text{Period } = \frac{2 \pi}{|} B | = \frac{2 \pi}{\frac{1}{3}} = 6 \pi$

$\text{Phase Shift } = - \frac{C}{B} = 0$

$\text{Vertical Shift } = D = 0$

graph{-3 sin (x/3) [-10, 10, -5, 5]}