Cracking The SAT Premium

You may have realized how easy these problems would become if you simply put them into your graphing
calculator. If calculator use is allowed, type in the function; if not, remember the four simple rules for
transforming graphs.

You could also plug in points to find the correct graph.

Forms of Equations

The SAT will ask questions using two different forms of the equation for a parabola.

The standard    form    of  a   parabola    equation    is:

y   =   ax^2    +   bx  +   c

In the standard form of a parabola, the value of a tells whether a parabola opens upwards or downwards
(if a is positive, the parabola opens upwards, and if a is negative, the parabola opens downwards).

The vertex  form    of  a   parabola    equation    is:

y   =   a(x −   h)^2    +   k

In  the vertex  form,   the point   (h, k)  is  the vertex  of  the parabola.

Simply knowing what the vertex form looks like may help you answer a question, like the following
example.