Standard form of a quadratic f(x) = ax^2 + bx + c In a quadratic function you find the vertex using the formula x = -b/2a; once you find the x value, substitute it into the equation and solve for y. To know if a parabola opens up or down you look at the coefficient of the x^2 term. If it is positive, the graph opens up; if it is negative, the graph opens down.
