16Hit1600
Advanced MathMediumSymmetry of an absolute-value function

Advanced Math practice question

The function g is defined by g(x) = |x − a|, where a is a constant. If g(2) = g(10), what is the value of a?

Answer: 6

|x − a| is symmetric about x = a, so equal outputs at 2 and 10 mean a is midway: a = (2 + 10)/2 = 6.

Common wrong answers

If you answered 4
4 is half of 8, the distance from a to each input, not a itself.
If you answered 8
8 is 10 − 2, the distance between the inputs.
If you answered 12
12 is 2 + 10, forgetting to halve.

More Advanced Math questions

Not affiliated with the College Board. SAT is a trademark of the College Board.