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# Help!

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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 $\frac{b}{a}$.

Lightning  Jun 16, 2018
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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!
TheXSquaredFactor  Jun 17, 2018