the function h(d)= -0.002d^2 +0.4d , where h is the height of the ball in meters , and d is the horizontal distance the ball travels in meters.

Question

h(d)=-0.002d²+0.4d

Answer 1

I assume you want h_max, which is at the vertex of the parabola.  At the vertex,

 

d = -0.4/[2(-0.002)]

 

Evaluate h(d) at this value of d to get h_max.