Originally Posted by

**mcdanielnc89** Okay, I started over. Let's see if I can do it this time...

How to find the vertex of a parabolic equation is "**y = ax^2 + bx + c**".

As you have stated we should recall the vertex form of a parabola which is "**y = a(x - h)^2** **+ k**".

**(h, k) **is the vertex of the parabola.

We need to rewrite "**ax^2 + bx + c**" in vertex form.

First we start by grouping the first two terms together: "**5.71x^2 + (- 3.135)x^2 + c**".

Now we pull out a common factor a: "**5.71 (x^2 + (-3.135 / 5.71x) + c**".

Complete the square: "**5.71 (x^2 + (-3.135 / 5.71x + (-3.135^2 / 4(5.71^2) + -5.64 - (-3.135^2) / 4(5.71)**".

Then, we end up with "**5.71 (x + (-3.135) / 4(5.71))^2** **+ -5.64 - (-3.135^2 / 4(5.71)**".

So, our vertex would be "**(-(-3.135) / (2(5.71)), -5.64 - (-3.135)^2 / (4(5.71))**", which would be "**(.27, -5.209692526 which is -5.21)**".

Have I gotten this much right?