# Finding Equation for parabola

• Dec 5th 2009, 10:03 PM
RenSully
Finding Equation for parabola
"Find the equation of the parabola with vertex at the origin that passes through the point http://college.hmco.com/blackboard/t...s/hl2122_1.gif and opens to the right."

At first I used the standard form of the equation of a parabola and I got
(y-9)^2=4p(x-9)

So is my next step trying to find the focus? And how?
• Dec 5th 2009, 10:08 PM
VonNemo19
Quote:

Originally Posted by RenSully
"Find the equation of the parabola with vertex at the origin that passes through the point http://college.hmco.com/blackboard/t...s/hl2122_1.gif and opens to the right."

At first I used the standard form of the equation of a parabola and I got
(y-9)^2=4p(x-9)

So is my next step trying to find the focus? And how?

Hey again Ren!

Notice that the vertex is at the origin. .

This implies the equation

$(y-0)^2=4p(x-0)$
• Dec 5th 2009, 10:24 PM
RenSully
Hello again :)

Oh I see. So, does that mean p=9?

If I use p=9 I get y=36x...
• Dec 5th 2009, 10:27 PM
VonNemo19
Quote:

Originally Posted by RenSully
Hello again :)

Oh I see. So, does that mean p=9?

If I use p=9 I get y=36x...

.

Not quite. You were given the point $(9,9)$. Use this to solve for p.

$(9)^2=4p(9)$