Question

Use completing the square to find the maximum height of the projectile: -16t^2+64t+80

Answer 1

ok... so you are being asked to find the vertex of the parabola, by putting it into vertex form.

so

\[y = -(16t^2 - 64t + ?) + 80\]

so \[16t^2 = (4t)^2 \]

so you need to find the value of the the last term

remember (a - b)^2 = a^2 - 2ab + b^2

you know a = 4t find b

Answer 2

how would I find b? plug in 4t into A?