Which of the following is the equation of the axis of symmetry of the quadtratic equation: y = 2x^2-12x+22?
A. x = -3
B. x = 3
C. x = -4
D. x = 4

Question

Which of the following is the equation of the axis of symmetry of the quadtratic equation: y = 2x^2-12x+22?
A. x = -3
B. x = 3
C. x = -4
D. x = 4

mathteacher1729 · Answer

Are you allowed to graph it??

anonymous · Answer

No

mertsj · Answer

This parabola is concave upward.
Therefore the axis of symmetry is a vertical line.  It goes through the vertex so find the x coordinate of the vertex using the formula x = -b/2a.  That is your axis of symmetry.

mathteacher1729 · Answer

After you use the formula, I recommend graphing to verify your answer.  Without some sort of picture to look at, it can really feel like you're just plugging numbers into meaningless formulas and getting meaningless answers. Good luck. :)

anonymous · Answer

Thanks for your help everyone. :) Much appreciated.

mertsj · Answer

yw.  What did you get?

anonymous · Answer

Still working it. >.< I'm slow at this sort-of stuff.

mertsj · Answer

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