Posted by **Tim** on Wednesday, April 30, 2008 at 8:40pm.

Can someone tell me if I am right?

I need to find the equation of a parabola. I am not sure if this is the correct way or if I have the correct answer.

Vertex at origin, focus is at (0,3)

Equation of parabola

vertex (0,0) focus (0,3)

focus (h,k+p)

(0,0+3)

y=0-3

directrix y=-3

a=(1/4)(p)

a=(1/4(-3))=(-1/12)

a=(-1/12) h=0 k=0

y=(-1/12)(x-0)^2+0

my answer is: y=(-1/12)(x^2)+0

- Algebra -
**Reiny**, Wednesday, April 30, 2008 at 9:09pm
shouldn't your parabola open upwards ?

your -1/12x^2.... makes it open down.

I do it this way:

let P(x,y) be any point on the parabola

by definition, the distance from P to the focal point is equal to the distance to the directrix --->

√(x^2 + (y-3)^2) = √(y+3)^2)

square both sides, and simplify to get

y = (1/12)x^2

## Answer This Question

## Related Questions

- algebra problem - I need to find the equation of a parabola. I am not sure if ...
- Algebra II - In this set of eight problems, we have to match each equation with ...
- Calculus - Great! I understand now that C0=f(a) c1=f'(a) c2=f"(a)/2 Now, If I am...
- Algebra - Could someone correct my answers and help with the other problems? 1. ...
- math,help - on one of last week homeworks i got this one wrong can someone ...
- Algebra - I'm trying this again, I'd like the quadratic form, so i can then work...
- Algebra - I think I have the correct equation, but can someone please double ...
- math check again please - I have a slope of -3/4 and the y-intercept at 8 the ...
- Algebra - Could someone correct my answers and help with the other problems? 1. ...
- college algebra--need help please!! - solve the following exponential equation. ...

More Related Questions