Question

http://prntscr.com/nbhuh0

Answer 1

@Vocaloid

Answer 2

Start with the general form ax^2 + bx + c

Identify your a, b, and c terms by comparing the general form with the equation in the problem (be careful about negative signs)


Then the x-coordinate of the vertex is -b/(2a)

Then plug the x-coordinate into the equation to get max height

Answer 3

\[h(t)= -4.9t ^{2}+20t+65\]

\[h^{'}(t)=-9.8t+20\]

\[h ^{'}(t)=0\]

when

t=20/9.8=2.04

The maximum height is

=\[-4.9*2.04^{2}+20*2.04+65=85.41m\]