SAT Question 50418728: Nonlinear Functions answer and explanation with Desmos solution

The y-intercept of the graph of a function in the xy-plane is the point where the graph crosses the y-axis. The graph of the polynomial function shown crosses the y-axis at the point $\left(0,-3\right)$. It's given that the y-intercept of the graph is $\left(0,y\right)$. Thus, the value of $y$ is $-3$.