Given:
[tex]f(x)=-0.015x^2+1.25x+2[/tex]
For the maximum :
[tex]\begin{gathered} f^{\prime}(x)=0 \\ f(x)=-0.015x^2+1.25x+2 \\ f^{\prime}(x)=-0.015\times2x+1.25 \\ f^{\prime}(x)=-0.03x+1.25 \end{gathered}[/tex]
For the maxima point :
[tex]\begin{gathered} -0.03x+1.25=0 \\ x=\frac{1.25}{0.03} \\ x=\frac{125}{3} \end{gathered}[/tex]
At x=125/3 football achived maximum height.
so maximu height is:
[tex]\begin{gathered} f(x)=-0.015x^2+1.25x+2 \\ =-0.015\times(\frac{125}{3})^2+(1.25\times\frac{125}{3})+2 \\ =-26.04+52.08+2 \\ =28.04 \end{gathered}[/tex]
Maximum height achived is 28.04