## Thursday, October 25, 2007

### St. Louis Arch

The St. Louis Arch equation has been found. First we found the equation using our original method discussed in class yesterday (using the vertex to find the standard equation, and then solving for "a"). Then we introduced using Matrices to solve a quadratic equation. This was a brief introduction to Matrices, as we will spend an entire chapter on them next semester, but it is important that you see how useful they can be for solving Systems of equations and Quadratics.

If you were not in class you should visit the website on the right to see the steps in solving a Matrix.

We also analyzed these two equations (one from each method), and discussed the importance of "a" in the equation, and why the vertex is almost irrelevant! It all depends on exactly how you set up the graph, but you will always have the same parabola, as long as your "a" is the same. The other numbers just give you the transformations!!!

Have a great time at the Fall Festival!!!

Coming up:

- If you were not in class you should complete this worksheet (just numbers 1-6)

- Tomorrow we will use these same techniques to find another famous arch!!

Posting for Points:

Can you think of another famous arch? (Think fast food)

## Wednesday, October 24, 2007

### St. Louis Arch

Today we talked about quadratics some more, and specifically focused on how to find the equation if given only the graph. You should now be able to also apply these concepts to a word problem.

Tonight for homework you must determine the equation (a quadratic) representing the St. Louis Arch using the picture provided in class. Use our word problems from class to help you set up the equation.

Have a great night!

Coming up:
- Homework: Find the equation representing the St. Louis Arch
- We will begin looking at matrices tomorrow

Posting for Points:
Where is the St. Louis Arch?

## Tuesday, October 23, 2007

Today we finished talking about quadratics, specifically about how they move, and how to find the equation using two points from a graph. If you were not in class you definitely need to get some notes from someone, but you can check out the examples on pages 131-134. We focused on finding the x-intercepts and solving for "a" in the equation f(x)= a (x-h)^2 + k.

Let me know if you are still confused (when you post your comment) and I will post some examples tonight.

Have a great week!

Coming up:
- HW pg. 135 #'s 36-42 even, 78, 79, and find the x-intercepts from last nights homework (14-24)
- Tomorrow we will look at using Matricies to solve quadratics

Posting for Points:
From the standard equation of a quadratic, what do h and k tell you?

## Monday, October 22, 2007

Today we focused on the specifics of a Quadratic function. We talked about both the "normal" equation and the standard equation. Be sure that you know how to use each, and how to change from one type to the other. You should also know what the vertex and the axis of symmetry are in a quadratic function. If you missed the notes today get them from someone ASAP.

Have a great week!

Coming up:
- Homework p. 134 #'s 9, 14-26 even

Posting for Points:
What is the equation for finding the axis of symmetry?