# The height of a ball (in meters) t seconds after it is thrown is given by y(t)=-4.9t^2+11.6t+22.5. From what height was the ball thrown?

$y \left(t\right)$ is the height of the ball at any time $t$.
When thrown initially (when $t = 0$), the height will be
$y \left(0\right) = - 4.9 {\left(0\right)}^{2} + 11.6 \left(0\right) + 22.5 = 22.5$