Answer:
5 feet
Step-by-step explanation:
The function which governs the T-shirt's height y, in feet, after x seconds is given as:
[tex]y = -16x^2+72x + 5[/tex]
We want to determine the starting height of the T-Shirt. This occurs at x=0.
When x=0
[tex]y = -16(0)^2+72(0) + 5\\y= 5$ feet[/tex]
The starting height of the t-shirt is 5 feet.