Answer:
The ball was thrown from a height of [tex]3\; {\rm ft}[/tex].
Step-by-step explanation:
The expression for the height of this ball, [tex]h(t) = -16\, t^{2} + 40\, t + 3[/tex], represents a parabola (with respect to time [tex]t[/tex].)
In this expression, "[tex]3[/tex]" represents the [tex]y[/tex]-intercept of the parabola- the output of the parabola when the input is [tex]t = 0[/tex]. The reason is that when [tex]t = 0\![/tex], terms of this parabola that include [tex]t[/tex] ([tex](-16\, t^{2})[/tex] and [tex]40\, t[/tex]) would evaluate to [tex]0[/tex]:
[tex]\begin{aligned}h(0) &= -16\times 0^{2} + 40\times 0 + 3 = 3\end{aligned}[/tex].
In the case of this ball, the term "[tex]3[/tex]" means that height of this ball is [tex]3\; {\rm ft}[/tex] when [tex]t = 0[/tex] (right when the ball was thrown.) Thus, the ball was thrown from a height of [tex]3\; {\rm ft}[/tex].