Hi,
Highly recommend the following, if You do not have a graphing calculator
FREE graph software https://www.padowan.dk/download/
s(t) = −16t2 + 64t + 47 |format at^2 + bt + c
Apply: b/-2a
x = 2 is the x value of the maximum
Using Your graphing calculator, evaluate s(2)
s(2) = 111 ft
In this case completing the Square is doable:
y = -16(t-2)^2 + 111
can read max point off that (2,111) Know it opens downward as a = -16
Wish You the Best in your Studies.