Posted by **Natalia** on Sunday, November 30, 2008 at 3:02pm.

Thanks to those who helped with my question: y+3=-1/12(x-1)^2. The only thing I am still unsure of is how to write the equation for the directrix. Do I just simply write 0=3-3, (the values plugged in for y=k-p). Thanks again for your help!!

- Algebra -
**Natalia**, Sunday, November 30, 2008 at 3:03pm
Whoops and one thing I forgot. Is it allowed for a parobala to open upward and have the directrix intercept it? Since p is greater than zero, it would have to open upward, but then the directrix would intercept the parobala (the directrix follows the x axis, and is at zero y)

- Algebra -
**Damon**, Sunday, November 30, 2008 at 3:09pm
p = Negative. (I called p a but same difference)

I showed you that this parabola opens downward in my explanation of the axis of symmetry at x = 1

the directrix is a horizontal line (m=0)

y = 0 x + 0

or

y = 0

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