00:01
So they give us this equation, h equals negative 16t squared plus 96t.
00:10
And a good student will be able to recognize pretty quickly that the y intercept is zero.
00:16
And with a negative a value, we're going to go up and then the graph is going to come back down.
00:22
So there's two different questions they're asking is, what is the maximum height? so that's a question.
00:28
And then when does it get back to the ground? and i'm going to try and answer this pretty quickly.
00:34
So the first thing you would do to figure out the maximum height is the time it takes to get there, which is the equation negative b over 2a.
00:42
So i'll get a negative 96 divided by 2 times negative 16.
00:47
So it's negative 96 divided by negative 32, which is exactly three seconds.
00:55
Now it doesn't ask for that time, i don't think.
00:59
It's asking what the height will be.
01:02
Well you figure out the height by plugging in three in for those t's and just make sure you square before you multiply...