Answer: The rocket will reach its max after 4 seconds
Explanation:
Hi, to find the maximum height, we have to set the first derivative of the equation equal to zero.
y=-16x^2+128x+136
0 = (2)-16x +128
0= -32x+128
Solving for x:
32x = 128
x = 128/32
x = 4 seconds
The rocket will reach its max after 4 seconds
Feel free to ask for more if needed or if you did not understand something.