The graph of the equation $y =ax^2 + bx + c$, where $a$, $b$, and $c$ are constants, is a parabola with axis of symmetry $x = -3.$ Find $\frac{b}{a}$.
How are you doing today, Lightning?
You may know that you can determine the equation of the axis of symmetry of any parabola by knowing that \(x=\frac{-b}{2a}\) . In this case, the axis of symmetry is already given: \(x=-3\) .
Since \(x=-3\) and \(x=\frac{-b}{2a}\), \(\frac{-b}{2a}=-3\) . The only task left is to solve for b/a .
\(\frac{-b}{2a}=-3\) | Multiply by 2 on both sides. |
\(\frac{-b}{a}=-6\) | We are almost there! Multiply by -1 to inverse the sign. |
\(\frac{b}{a}=6\) | There you go! |