Algebra 2 question - please help

hint..

x= -b/2a

remember vertex form of a quad equation?

(x-h)^2 +k

I'm thinking 250 - 10*(x-4)^2. Or, 90 + 80x - 10x^2.

a square + b square divided by c squared.

You are welcome.

How do i figure out what A and B are?

By looking at my answer.

sorry you need a(x-h)^2 +k vertex form look it up in your book .. solve for (a)

ok.. that's all.. not going to do your homework

this is your clue for solving for (a)

The rocket touches the ground at a horizontal distance of 9 feet from the cliff

all i have in my book is ax squared + bx + c = y... i think a=4 but i cant convert it into quadratic formula and get correct values for x and y.

rocket man wrote:

all i have in my book is ax squared + bx + c = y... i think a=4 but i cant convert it into quadratic formula and get correct values for x and y.

No, a = -10, as it does in the very much correct answer I have already posted in this thread.

Draw yourself a picture. This one really isn't very complicated.

rocket man wrote:

all i have in my book is ax squared + bx + c = y... i think a=4 but i cant convert it into quadratic formula and get correct values for x and y.

But, if you want to go the long way about this and considering that your book sucks for not discussing the relation of the vertex point to the form of a quadratic...

If you go from the hint "y = a(x-h)^2 + k", he means h is the x-coordinate of the vertex and k is the y-coordinate of the vertex, while y is the height of the rocket and x is the horizontal distance from the edge of the cliff. So, h = 4 and y = 250. Thus, we have y = a(x-4)^2 + 250.

Now, when x = 9, y = 0, so 0 = a(9-4)^2 + 250. Which, solving for a, gives that a = -10. We end up with y = -10(x-4)^2 + 250.

Ok thanks. I got it now.