# Week 8 in Prec 11

In week 8, we learned the analyzing quadratic functions.

First of all , we should find the vertex out. It’s the most important thing in a quadratic function, and then, we should find out the x-intercept if necessary. It can help us to figure out the rough shape of the quadratic functions.

We have three forms:standard form, general form and factored form.

$y=a(x-p)^2+q$ can tell us the vertex; $y=ax^2+by+c$ can tell us the y-intercept is c; and the $y=a(x-x_{1})(x-x_{2})$ can tell us the x-intercept if it has.

After we have found three or more points besides the vertex, we can draw it , use smooth curves.