Answer:
(a)Vertex
(c)3 seconds
Explanation:
Part A
The maximum point on a parabola is called the Vertex.
Part C
To find out how much the plain was in the air, find the values of t at which the height, h=0.
Next, subtract the second value of t from the first value.
[tex]h=-16t^2+32t+48[/tex]First, set h=0:
[tex]\begin{gathered} h=-16t^2+32t+48=0 \\ -16t^2+32t+48=0 \end{gathered}[/tex]Factorize:
[tex]\begin{gathered} -16(t^2-2t-3)=0 \\ t^2-2t-3=0 \\ t^2-3t+t-3=0 \\ t(t-3)+1(t-3)=0 \\ (t+1)(t-3)=0 \\ t+1=0\text{ or }t-3=0 \\ t=-1\text{ or }t=3 \end{gathered}[/tex]Therefore, the plane hits the ground after 3 seconds.
