Algebra question

Question

(1 point) A toy rocket is launched straight up from the roof of a garage with an initial velocity of 80 feet per second. The height hh of the rocket in feet, at tt seconds after it was launched, is described by h(t)=−16t2+80t+10h(t)=−16t2+80t+10. Find the maximum height of the rocket. h=h=  feet

Answer 1

h'(t) = -32t + 80 = 0

t = 80/32 = 5/2 seconds

h(5/2) = -16(5/2)^2 +80(5/2) + 80 = 110 feet= maximum height