Answer:
t = 1.1 sec for first time and then in
t = 3.9 sec
Step-by-step explanation:
The function for the height of the circus performers is:
[tex]h(t) = -16t^{2} +80t +32[/tex]
where t is seconds after launch
h is height in feet
For calculating after how many seconds is the performer at 100 feet above the ground, we must equal the equation to 100 and to find t:
Then,
[tex]100 = -16t^{2} +80t+32[/tex]
[tex]0 = -16t^{2}+80t -68[/tex]
[tex]t = \frac{-80\ \pm \\\sqrt{80^{2}-4(-16)(-68) } }{2(-16)}[/tex]
t = 3.9 sec
t = 1.1 sec
