Answer:
Max height = 128feet
Time = 0secs
Step-by-step explanation:
Given the height in ft of a rocket after x seconds is given by y=128-16x^2, at maximum height, the velocity of the object is zero that is;
dy/dx = 0
0 - 32x = 0
x = 0/-32
x = 0
Hence the time taken for the object to reach its maximum height is 0 secs
To get the maximum height reached, you will substitute x = 0 into th expression given as shown;
y = 128 - 16x^2
y = 128 - 16(0)^2
y = 128 - 0
y = 128feet
Hence the maximum height reached by the rocket is 128feet