Post for Class on 11/20/09

We began class by looking at a few blogs created by other math classes. One was from a precalc class similar to ours, and theirs was far superior to what we have done so far. The web address for this blog is: http://pc40sw09.blogspot.com/search/label/Exponents%20and%20Logarithms, in case anyone is interested. We also went over the new rubric for second quarter blogging and talked about how we are planning on moving away from the wikispace and onto the blog.

Getting into the math, we went over the Supercorrection followup tests. Most of the mistakes people made were small, so it seems like we finished strong on that unit. We moved onto logarithms, and started off by looking at the website listed at the bottom of this post. This post goes over the four basic properties of logs and is a very helpful tool. However, this post as well as what Mr. O'Brien said in class goes to prove that y = log_bx if and only if b^y = x,

where x > 0, b > 0, and b 1 is the most important equation used in logarithms. After this, we did the problems p. 243/ 47-59 odd, 69-79 odd, and 80 in class with our groups. Although these problems could look a bit complicated to begin with, by using the four big properties we were able to break them down into a simpler form. Mr. O'Brien also showed us how working vertically instead of horizontally can make problems easier to solve and let us make fewer mistakes. Mr. O'Brien demonstrated how to simply break down problems by solving the problems p. 253/12, 14, 30, 56, 86, and 94 as practice problems.

Main lesson of the day: Even the most complex problems can be broken down into the four basic log properties.

Homework for next class:

p. 253/9-23 odd, 27, 29, 35, 49, 57, 65, 81, 93, 99

If you miss class, be sure to do p. 243/47-59 odd, 69-79 odd, 80 and p. 253/12, 14, 30, 56, 86, 94 as these will be included on homework quizzes for this unit.

Look over your homework in preparation for the quiz next class

Link to four properties: http://www.andrews.edu/~calkins/math/webtexts/numb17.htm