y = ax2 + bx + c
where a, b, and c are all real numbers and a ≠ 0.
Graph the function f(x) = 3x2 + 12x + 11
A quadratic function is often written in the form f(x) = a(x – h)2 + k, where a, h and k are real numbers and a ≠ 0. You may recognize this as the formula for the graph of a parabola. That is because the graph of every quadratic function is a parabola that either opens up or down.
Graph the function