Graphing Calculators and You
Oh NO! They use graphing calculators all the time in the book, but my evil teacher won't let me use one on the test. How is that going to work?
I'm getting quite a few questions from people who are getting kind of worried, since the videos (and to a lesser extent, the textbook) use graphing calculators a lot, and they are wondering (quite reasonably) how this is going to work on the test, or whether they are going to be "behind" in their math careers if they don't learn how to use one this semester. So, there are actually two questions here:
How will all those graphing calculator type problems work on the test?
Remember, the whole point of the graphing calculator is to draw a graph. Tha's it. (Well, it can do a bunch more, but for most of what we are doing, that's it.) The real point of all those problems isn't how to make your calculator draw the graph, but for you to look at the graph and understand what it's telling you. So, let's look at a problem from section 2.5:
Solve |2x + 1| > 1 graphically.
Well, to work this, you need to know what the graph looks like. You could graph it by hand (not all that hard, but kind of a pain) or you could use your graphing calculator. On the test, this question might look something like this:
Use the graph of f(x)=|2x + 1| to solve the inequality |2x + 1| > 1:
So, I gave you the graph; now you need to figure out where the y values of this graph are > 1. (Hint: The answer is: x < -1 or x > 0.) So, the point isn't how you got the graph (in the first case, you would use your calculator to find it, while in the second case, I gave it to you), the point is to use the graph to answer the question. Notice, this is really pretty similar to how they ask these kinds of questions in the online homework (you never actually have to use a graphing calculator in any of the online homework, though sometimes, you have to choose the right graph in a few multiple choice problems).
But if I don't learn how to use a graphing calculator now, won't I be behind in my later math classes?
Well, I suppose you could look at it like that, but if you don't learn to use it now, you'll just need to learn to use it then. So, if you don't spend a couple of hours figuring it out this semester, you will have to spend a couple of hours figuring it out some other semester. If you have access to a graphing calculator (you can check them out for limited time periods from most ACC libraries), then I recommend you spend a little time learning to use one; it's a handy tool and kind of fun to fool around with (in a geeky sort of way). However, don't get sidetracked with this; it's just a tool - don't confuse learning to use a graphing calculator with learning college algebra. Learning the math is your goal, not learning the calculator. Some people find that using the calculator helps them learn the math better; if you can, give it a try and see if it helps you understand the math better. But you don't have to know anything at all about graphing calculators to learn college algebra. The graphing calculator isn't even particularly the best way to use technology to help with drawing graphs (though it does have the advantage of being fairly cheap and portable); there are computer programs you can use for free that will draw much better looking graphs with much more detail:
Mac - On the Mac, if you have a recent version of OS X, you can find a program called Grapher in your Applications or Utilities folder already (no downloads or money necessary).
Windows - You can download a program called Winplot here. It's free and does a lot of stuff. There are busloads of other programs out there as well, if you want to hunt them down...
So, remember, the point is the graph, not the calculator or computer program; what does the graph tell you and how can you use the graph to help solve the problem? The calculator or computer program are just ways to draw that graph without having to do much work on your part (definitely a Good Thing).