If a projectile is fired straight upward from the ground with an initial speed of 128 feet per second, then its height h in feet after t seconds is given by the function h(t)equalsnegative 16 t squared plus 128 t. find the maximum height of the projectile.
For this case we have the following function: h (t) = - 16t ^ 2 + 128t Deriving the function we have: h '(t) = - 32t + 128 Equaling zero we have: -32t + 128 = 0 We clear the time: t = 128/32 t = 4 Substituting in the height equation: h (4) = - 16 * (4) ^ 2 + 128 * (4) h (4) = 256 feet Answer: The maximum height is: h (4) = 256 feet