A softball is thrown up into the air. The ball's height in feet is modeled by the equation h(t) = -16t2 + 32t + 5.
h = height
t = time in seconds
Find the maximum height of the ball.
a) 8.3 feet
b) 12.2 feet
c) 7.6 feet
d) 13.9 feet

Question

A softball is thrown up into the air. The ball's height in feet is modeled by the equation h(t) = -16t2 + 32t + 5.
h = height
t = time in seconds
Find the maximum height of the ball.
	a)	8.3 feet
	b)	12.2 feet
	c)	7.6 feet
	d)	13.9 feet

anonymous · Answer

You sure the equation is right?  I keep ending up with 21 ft at 1.000001 seconds.

That's supposed to be $$-16t^2+32t+5$$
Right?

anonymous · Answer

Note that the height function is a quadratic.  The vertex of its graph is at x=-b/2a=-32/-32=1.  h(1)=21 feet, the maximum height.

anonymous · Answer

Your little extra number attached to the one is a calculator rounding error.

anonymous · Answer

Yeah, I would have thrown that out, but what I'm saying is his/her problem doesn't have the answer listed.

anonymous · Answer

I don't know what else the answer would be...

anonymous · Answer

Exactly.  I'd guess it is a typo in the equation or in the answers.  There is no other way to work the problem.