The equation for a projectile's height versus time is h(t)=-16t^2+Vot+ho A tennis ball machine serves a ball vertically into the air from a height of 2 feet, with an initial speed of 120 feet per second. After how many seconds does the ball attain its maximum height? Round to the nearest hundredth.

Question

phi · Answer

OK,  it's easy using calculus.  But another way is to find the vertex of the parabola. Can you do that?

anonymous · Answer

theres no graph

phi · Answer

Well, with a lot of work you could sketch one... But I think there is a formula. If you have an equation
a x^2 + b x +c  = 0 
then the vertex is -b/(2a) 
Have you ever seen this before?

anonymous · Answer

ya