Thread: Equation of a parabola

Vertex: (0,0); contains (-3,-4) and (-3,4)...
Find the equation.. Please help me or just give me an idea on how to do this problem... Thanks!

Originally Posted by lance

Vertex: (0,0); contains (-3,-4) and (-3,4)...
Find the equation.. Please help me or just give me an idea on how to do this problem... Thanks!

A parabola can be written as

$\displaystyle y = a(x - h)^2 + k$, where $\displaystyle h$ is the $\displaystyle x$ coordinate of the vertex and $\displaystyle k$ is the $\displaystyle y$ coordinate of the vertex.


So so far we know $\displaystyle y = a(x - 0)^2 + 0$

$\displaystyle y = ax^2$.


Now substitute one of the other points and solve for $\displaystyle a$.