If it isn't already, get your equation into the form ax 2 + bx + c, then plug a, b, and c into the formula x = (-b +/- SqRt(b 2 - 4ac))/2a. X Research source If you can't easily solve for your x intercepts or factor your equation, use a special equation called the quadratic formula designed for this very purpose. In this case, your only x intercept is -1 because setting x equal to -1 will make either of the factored terms in parentheses equal 0.In this case, your x intercepts are the values for x which make either term in parentheses = 0. Some equations in the ax 2 + bx + c form can be easily factored into the form (dx + e)(fx +g), where dx × fx = ax 2, (dx × g + fx × e) = bx, and e × g = c. x = 11 and 13 are the parabola's x-intercepts. This method may work for simple quadratic equations, especially in vertex form, but will prove exceedingly difficult for more complicated ones. Simply set f(x) = 0 and solve the equation.

Otherwise, solve for your x intercepts with one of the following methods: If your parabola has a vertex opens upward and has a vertex above the x axis or if it opens downward and has a vertex below the x axis, it won't have any x intercepts. However, not all parabolas have x-intercepts. Even if you're not to find them, these two points can be invaluable for drawing an accurate parabola. X Research source Often, on schoolwork, you'll be asked to find a parabola's x-intercepts (which are either one or two points where the parabola meets the x axis). If necessary, find and plot x intercepts. The coordinates of the vertex in standard form are given by: h = -b/2a and k = f(h), while in vertex form, h and k are specified in the equation. To graph either of these types of equations, we need to first find the vertex of the parabola, which is the central point (h,k) at the 'tip' of the curve.Two vertex form equations are f(x) = 9(x - 4) 2 + 18 and -3(x - 5) 2 + 1.Vertex form is so named because h and k directly give you the vertex (central point) of your parabola at the point (h,k). X Research source In this form, the quadratic equation is written as: f(x) = a(x - h) 2 + k where a, h, and k are real numbers and a does not equal zero. For example, two standard form quadratic equations are f(x) = x 2 + 2x + 1 and f(x) = 9x 2 + 10x -8.X Research source In this form, the quadratic equation is written as: f(x) = ax 2 + bx + c where a, b, and c are real numbers and a is not equal to zero.

The two forms of quadratic equation are: X Research source If you're doing a homework problem, you'll usually receive the problem in one of these two forms - in other words, you won't be able to choose, so it's best to understand both. You can use either form to graph a quadratic equation the process for graphing each is slightly different. The quadratic equation can be written in three different forms: the standard form, vertex form, and the quadratic form. Determine which form of quadratic equation you have.

Graphing quadratic functions