SOLUTION: I know that the formula to find the axis of symmetry is "-b/2a". Why is there a negative before the "b"?

Question 729452: I know that the formula to find the axis of symmetry is "-b/2a". Why is there a negative before the "b"?
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!

Consider the quadratic formula:

which tells us that the zeros of the quadratic equation, which are two points where the parabola intersects with the

axis, and which must, by symmetry, be equidistant from the vertex of the parabola that is the graph of the corresponding quadratic function.

Let's re-write the quadratic function slightly:

You should be able to see that the "equi-distant" part is the

part, and the point from which the zeros are equidistant, namely the vertex, is the

part.

John

Egw to Beta kai to Sigma
My calculator said it, I believe it, that settles it

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