It is important to factor out first and complete the square afterwards. And if there is a number in front of the ? So simply add the right number and subtract it at the same time. This does only work if there is the right number (the number completing the square).
Furthermore, one sees from this calculation that you just have to use the binomial formula backwards: Build a binomial formula out of the function term. :PĪs you can see, the x-coordinate of the vertex equals the number in brackets, but only up to change of signs. Here is an example:ĭein Browser unterstützt den HTML-Canvas-Tag nicht. You have to complete the square: Take the number in front of x, divide it by and square the result. This means: If the vertex form is, then the vertex is at (h|k). From the vertex form, it is easily visible where the maximum or minimum point (the vertex) of the parabola is: The number in brackets gives (trouble spot: up to the sign!) the x-coordinate of the vertex, the number at the end of the form gives the y-coordinate. The vertex form is a special form of a quadratic function.
