The Portuguese Subtitle video has been broken into two parts, you can view through the Language drop down menu above.

This lesson aims to help students with quadratic functions y = ax^{2} + bx + c. This is the next step after linear functions bx + c. The lesson begins with three quadratics and their graphs (three parabolas): y = x^{2} - 2x + (0 or 1 or 2). The prerequisite or co-requisite is some working experience with algebra, like factoring x^{2} -2x into x(x-2). The objective is to connect four things: the formula for y, the graph of y (a parabola), the roots of y and the minimum or maximum of y. The particular example y = x^{2} – 2x could be repeated by the teacher, for emphasis. The lesson will take more than one class period (and this is deserved!). The breaks allow time to consider parabolas starting with -x^{2} and opening downward. A physical path would be one (dangerous?) activity.