16Hit1600
Advanced MathEasy–MediumAxis of symmetry of a parabola in standard form

Advanced Math practice question

In the xy-plane, the graph of f(x) = 3x² − 12x + 7 is symmetric about the vertical line x = k. What is the value of k?

Answer: 2

The axis of symmetry is x = −b/(2a) = 12/6 = 2.

Common wrong answers

If you answered 4
4 is −b/a, forgetting the 2.
If you answered 7
7 is the constant term.
If you answered -2
−2 has the wrong sign; −b/(2a) = −(−12)/6.

More Advanced Math questions

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