The line of symmetry is the vertical line x = h, and the vertex is the point (h,k).
Any quadratic function can be rewritten in standard form by completing the square. (See the section on solving equations algebraically to review completing the square.) The steps that we use in this section for completing the square will look a little different, because our chief goal here is not solving an equation.
Note that when a quadratic function is in standard form it is also easy to find its zeros by the square root principle.