SAT Question 70fb357b: Nonlinear Functions answer and explanation with Desmos solution

Choice A is correct. The y-intercept of a graph in the xy-plane is the point where $x=0$. Substituting $0$ for $x$ in the given equation, $y=576^{\left(2x+2\right)}$, yields $y=576^{\left(2\left(0\right)+2\right)}$, which is equivalent to $y=576^2$, or $y=331,776$. Therefore, the graph of the given equation in the xy-plane has a y-intercept of $\left(0,331,776\right)$. It follows that $r=0$ and $s=331,776$. Thus, the equivalent equation $y=331,776^{\left(x+1\right)}$ displays the value of $s$ as the base.