SOLUTION: If the vertex of a parabola is (-1,-7) how can I find the equation of the parabola? Is this possible?

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: If the vertex of a parabola is (-1,-7) how can I find the equation of the parabola? Is this possible?      Log On


   

Question 530867: If the vertex of a parabola is (-1,-7) how can I find the equation of the parabola? Is this possible?
Found 2 solutions by jim_thompson5910, josmiceli:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
You would need another point that lies on the parabola to find the equation of the parabola.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Not quite, the x-coordinate of the vertex is
+-b%2F%282a%29+ when the general formula
for the equation is +y+=+ax%5E2+%2B+bx+%2B+c+
So I have:
+-b%2F%282a%29+=+-1+
+b+=+2a+
the y coordinate is +-7+, so
+-7+=+a%2Ax%5E2+%2B+2a%2Ax+%2B+c+
+a%2Ax%5E2+%2B+2a%2Ax+%2B+c+%2B+7+=+0+
I can still only get a formula for the roots in terms
of a and c, so there can be many equations
that have (-1,-7) for a vertex