Question 258057
h = 16t^2 + 45t + 40
dh/dt = 32t + 45. When dh/dt = 0, h is a stationary point
this is at t = 45/32 = 1.406 seconds
so h = 32 x(1.406^2 + 45x 1.406 + 40 = 63.25 + 63.27 + 40 = 166.52 feet