recall that we find the $y$-intercept of a quadratic by evaluating the function at an input of zero, and we find the $x$-intercepts at locations where the output is zero. we can also confirm that the graph crosses the $x$-axis at $\left(\frac{1}{3},0\right)$ and $\left(-2,0\right)$. find the $x$-intercepts of the quadratic function $f\left(x\right)=2{x}^{2}+4x – 4$.
when applying the quadratic formula, we identify the coefficients $a$, $b$, and $c$. the ball’s height above ground can be modeled by the equation $h\left(t\right)=-16{t}^{2}+80t+40$. the rock’s height above ocean can be modeled by the equation $h\left(t\right)=-16{t}^{2}+96t+112$.