Precalculus (10th Edition)

amplitude: $3$ period:$\dfrac{\pi}{2}$
If a function has form $y=A\sin(\alpha x)$, then there $|A|$ stands for the amplitude and $T =\frac{2\pi}{\omega}$ stands for the period. Hence, here we have $|A|=|3|=3$ $\omega=4$, thus $T=\dfrac{2\pi}{4}=\dfrac{\pi}{2}$