Monday, February 9, 2009

Monday, February 9

Hello, Pre-cal Buddies, well my name is Karen and I am your scribe for today. Sorry to disppoint you guys, but my scribe post will be nothing compared to Mr. mest's. I guess you guys are going to start over the whole beating the record for the consecutive Scribe Post Hall of Fame.

So, we started the class by talking about the Scribe Post Hall of Fame, which is pretty much a site "for great scribes". Mr. Kuropatwa talked about what you need on your scribe post to be nominated. Your scribe post should be well explained, engaging, have good content, and you should also have the message delivered properly.

Another thing we talked about before our actual Pre-Cal Lesson started was the website where you can check out the curriculum. It's like an online text book where you can study any courses online.
Here's the link to the website:
Log-in: Demo
Password: Demo

We started today's class from where we left off during Friday's class: Tangents.
Now, how do we get Tangent you may ask?
We all know SOH CAH TOA

From what we've been learning from our previous lessons, we know that
Sine=y-axis and that Cosine=x-axis.
After reading Aldrin's post, you should know that

so we can rewrite this equation as

Is There A Pattern?
Sine, as we move up the y-axis, the numerator goes up by 1, and is a square root. The denominator is always 2.
Cosine, the pattern is the same as the pattern for Sine, except it moves up along the x-axis.

Now, how about
Alex had a really clever idea, he said that as you go down, you divide by root3 , and as you move up, you multiply by root3.
Mr. Kuropatwa said that the pattern that he remembered was that Tan was 1/root3 when it was closest to the x-axis. That is, when root3 is down low. When tan was root3/1
, that is when it was farthest from the x-axis, that's when root3 is up top.


After talking about Tangents, we had a Mental Math. The following questions were asked:
1.) sin pi/6
2.) cos pi/3
3.) sin 2pi/3
4.) cos 3pi/4
5.) sin 11pi/6
6.) tan pi/4
7.) cos pi/2
8.) sin pi
9.) cos -pi/3
10.) sin -3pi/4

After the mental math, we talked about ...

The "Other Trig Function" is not that hard to understand, they're just the reciprocals of Sine, Cosine and Tangent. An easy way to know which is the reciprocal of which is by remembering that
S goes with C, and C goes with S. What I mean by this is that Sine goes with Cosecant, and Cosine goes with Secant.

Because Cosecant is just a reciprocal of Sine, their signs will not change. So for the question:
They would still fall in the same quadrant. These two questions are not the same, but they are related.


After talking about the Other Trig Functions, Mr. Kuropatwa gave this question to answer on the smart board.To solve this question, we can use the equation of the unit circle, And since it keeps on coming up in our discussions in class and because I too, mentioned it earlier, I'm sure that it is drilled into everyone's head that sin=y and cos=x. So, we can re-write this equation as,


The following questions were given to us, and what we had to do were figure out the exact values for each of the following, and multiply/divide/add/subtract them, which ever one the question asks us to do.

And, this last image is just a copy of the second question above, but it was re-written in a better and neater form. It is clear that having a good form when it comes to writing equations comes in handy once you get into way more complex equations. It will be much easier to see what you're doing, and mistakes can be easily spotted.

That's all I guess, I apologize for the fact that this scribe post was really really really really late, and that it wasn't great. I really just had too much things happening at once, and even if I didn't, I wouldn't have been able to make this scribe post great. For our next scribe, I pick you.. JOHN L.

.. k bye.


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