Answer:
3 secs
Explanation:
Given the height of the T-shirt represented by the equation
h(t) = -16t² + 96t + 6
velocity v(t) =

v(t) = -32t+96
At maximum height, the velocity of the t-shirt is 0ft/s
Substitute v= 0 into the velocity function and calculate the value of t:
0 = -32t+96
Re-arrange
-32t+96 = 0
-32t = -96
t = -96/-32
t = 3secs
Hence it takes 3seconds for the T-shirt to reach its maximum height.