SOLUTION: When you graph a quadratic function and find the vertex is on the Y-axis, you know for sure that? I think that we know for sure that the coefficient of the x term ("b") is zero; O

Algebra ->  Coordinate-system -> SOLUTION: When you graph a quadratic function and find the vertex is on the Y-axis, you know for sure that? I think that we know for sure that the coefficient of the x term ("b") is zero; O      Log On


   

Question 48215: When you graph a quadratic function and find the vertex is on the Y-axis, you know for sure that?
I think that we know for sure that the coefficient of the x term ("b") is zero; OR
The roots of the equation is the positive and negative of the same number (+p and -p).
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Well, the answer is one or both of the above.
If the vertex of the parabola is on the y-axis, then, if the parabola intersects the x-axis, it does so at +x and -x and the coefficient of x (b) is 0.
If the parabola doesn't inersect the x-axis, but the vertex is on the y-axis, then the coefficient of x (b) is 0.
See the graphs below of y+=+x%5E2-2 (red) and y+=+x%5E2%2B2 (green):
graph%28300%2C200%2C-5%2C5%2C-10%2C10%2Cx%5E2-2%2Cx%5E2%2B2%29