Sometimes equations come dressed up as y = (x - h)² + k (that’s vertex form). No problem! The axis is simply x = h. That’s the same “h” that’s hiding inside the parentheses. So if you see y = (x - 3)² + 5, the axis is x = 3. Easy peasy lemon squeezy.
Axis Of Symmetry Formula Intercept Form
And if the equation is something like y = 2(x + 1)² - 4, then h = -1 (because x + 1 is really x - (-1)). Axis: x = -1. Two negatives make a positive? No, they make a correct answer.
