A projectile is launched from a platform 12 feet high with an initial velocity of 104 feet per second,
The height h of the projectile at t seconds after launch is given by h = –16t
2
+ 104t + 12 feet.

(a) How many seconds after launch does the projectile attain maximum height?
(b) What is the maximum height?

Question

A projectile is launched from a platform 12 feet high with an initial velocity of 104 feet per second, 
The height h of the projectile at t seconds after launch is given by h = –16t
2
 + 104t + 12 feet. 
 
(a) How many seconds after launch does the projectile attain maximum height?
(b) What is the maximum height?

jdoe0001 · Answer

have you covered quadratic equations yet?

anonymous · Answer

Yes. Do we solve this just like any other quadratic using the equation?

jdoe0001 · Answer

well, notice is a quadratic equation, thus is a parabolic graph

the leading term has a negative coefficient, meaning the graph is going downward
thus |dw:1405124426534:dw|   so if we just find the vertex of the parabola

the y-coordinate wil be how high it went up

x-coordinate will be how long in seconds it took to get there