Answer
$a=-3$, $b=2$ and $c=0$
Work Step by Step
From the graph, since the graph from origin, the graph is then downward, and the amplitude is $3$, $a=-3$.
Rewriting the function $f(x)=a\sin b\left(x-\frac{c}{b}\right)$ and from the graph, the period is $\pi$:
$$period=\frac{2\pi}{b}$$ $$b=\frac{2\pi}{period}=\frac{2\pi}{\pi}=2$$
From the graph, there is no shift, so $c=0$.
Thus, $a=-3$, $b=2$ and $c=0$.
