Answer
$y=-1-\frac{1}{2}\ sin(\frac{3}{2}x)$
Work Step by Step
Step 1. Shift the curve 1 unit up, we can see the new curve will be odd and decreases while passing $(0,0)$, thus we can write a general form $y=-1-A\ sin(kx)$
Step 2. We can identify the amplitude $A=\frac{1}{2}$.
Step 3. We can identify the period $p=\frac{4\pi}{3}$, thus $\frac{2\pi}{k}=\frac{4\pi}{3}$ and $k=\frac{3}{2}$
Step 4. The equation is $y=-1-\frac{1}{2}\ sin(\frac{3}{2}x)$
