Answer:
144 ft
Step-by-step explanation:
The object's maximum height is the same as the y-coordinate of the vertex.
To find that, first, finds the x- coordinate(t).You can find it by: first identifying a, b and c.
Multiply the b by negative 1 or simply change its sign and divide it by 2a.
Afterward, plug the answer in the equation to find y, your answer.(ax+bx²+c=-16t²+64t+80).
Therefore, a=-6, b= 64 and c=80-64/2(-16)=-64/-32=2-16(2)²+64(2)+80=144 ft
So the maximum height of the object, when launched 64ft/sec from a platform that is 80 ft high, is 144 ft