Verified Answer :

Maximum of function \(f(x)=ax^2+bx+c\) where \(a eq 0\) you can find by using this formula: \(y_{\max}= - \dfrac{\Delta}{4a}=-\dfrac{b^2-4ac}{4a}=\dfrac{4ac-b^2}{4a}=c-\dfrac{b^2}{4a}\)

In height function you've got:

a= -16
b= 200
c= 4

Just substitute! You'll get

\(y_{\max} = 4 - \dfrac{200^2}{4 \cdot (-16)}=4-\dfrac{40 \ 000}{-64}=4+\dfrac{40 \ 000}{64}=4+625=629\)

Maximum height is  629  [units]