What is the highest the ball will go?

Question

Devin is practicing golf at the driving range. The equation that represents the height if his ball is s = -.5 squared + 12t where s is the distance in feet and t = time in seconds

Answer 1

I assume the equation is s=-.5t² + 12t

 

This is an inverted parabola and you need to find s-value (y-value) of the vertex of the parabola which is the maximum height. 

 

The t-value (x-value) of vertex can be found using the formula for finding the x-coordinate of the vertex of a parabola: s=-b/2a  = -12/(2*-.5) = 12

 

So at t = 12 seconds you will be at maximum height (s).

 

Plug 12 back into the equation for t and you get -.5(12)² + 12(12) = 72

 

Therefore, at time t = 12 seconds the ball will reach a maximum height of 72 feet.