Solve the Sin Equation: Amp, Period, Phase Shift, Vert Shift

[datafiend]

Homework Statement

Find the amplitude, period, phase shift, and vertical shift

Homework Equations

y=- $1/2$sin [3 (x-∏/2)] -2

The Attempt at a Solution

amp = -$1/2$, vertical shift is 2 down y-axis.

I can't get the period and ph. shift.

 

[HallsofIvy]

The "standard" sine function, sin(x), has one period starting at $x= 0$ and ending at $x= 2\pi$. The function sin(a(x- b)) has one period starting at $a(x- b)= 0$, or $x= b$ and ending at $a(x- b)= 2\pi$ or $x= b+ \frac{2\pi}{a}$.