h=-16t^2+80t+25

Question

Find H. An arrow was shot from a platform 25 feet above the ground at an initial speed of 80 feet per second. What is the maximum height of the arrow?

Answer 1

h=-16t^2+80t+25

This is a parabola that opens downward and the axis of symmetry, x= -b/2a = -80/(-32) = 2.5

Then the height of the vertex at x=2.5 is h(2.5) = 125.

That is the maximum height of the arrow, which is 125 feet.