Question

Find the equation of the parabola with focus (-3,1), and vertex (-4,1)

Answer 1

answer or method?

Answer 2

How to do it o;

Answer 3

here is the answer
http://www.wolframalpha.com/input/?i=parabola+focus+%28-3%2C1%29+vertex+%28-4%2C1%29

Answer 4

Tysm C:

Answer 5

actually this form is a little misleading so lets do it the right way
vertex is \((-4,1)\) and we know it opens to the right (because the focus is one unit right, namely \((-3,1)\) so we start with
\[(y-1)^2=a(x+4)\] and then we need to find \(a\)

Answer 6

in this case you have gone one unit to the right from the vertex to the focus, so \(a=4\times 1=4\) and so you should really write
\[(y-1)^2=4(x+4)\]

Answer 7

so if your parabola opens right with vertex at \((h,k)\) you know it looks like
\[(y-k)^2=a(x-h)\] and find \(a\) by seeing how many units you have gone to the right to get the focus, and multiply by 4

Answer 8

Much better xD Thanks again