Answer:3.59 s
Step-by-step explanation:
Given
height of rocket is given by
[tex]y=-16x^2+115x+130[/tex]
Rocket will be at it maximum height when [tex]\frac{\mathrm{d} y}{\mathrm{d} x}=0[/tex]
therefore
[tex]\frac{\mathrm{d} y}{\mathrm{d} x}=-32x+115=0[/tex]
[tex]32x=115[/tex]
[tex]x=\frac{115}{32}[/tex]
[tex]x=3.593\ s[/tex]
At [tex]x=3.59\ s[/tex] rocket will be at its maximum height