## Sunday, February 24, 2008

### BOB: Circular Functions

Since our test will be sometime this week, I decided to make my BOB entry before I forget. =)

In the beginning of this unit, I wasn't so comfortable converting degrees to radians. Up and till this unit I've always been using degrees but later in this unit, it became easy. This unit wasn't as bad as I thought it would be because from last year's precal I had trouble with circular functions. Now, I understand how to figure out certain word problems and convert degrees into radians and vice versa. I also found that finding the sine, cosine, and tangent of angles are pretty easy and it's probably because of the mini quizzes we had. But finding cosecant, secant, and cotangent can be a bit confusing at times and may take up a bit of time for me to figure out. What helps me a lot is to look for patterns to solve different kinds of questions which makes it much easier to do.

On the other hand, considering the fact that I missed a couple classes last week, I was a bit confused with the graphing we had to do. At first I was like, "what is this?" But after a few explanations and practicing doing questions I got the hang of it. Remembering DABC actually helped me a lot to do the problems. Yet, I'm not totally comfortable with graphing because it probably takes me more time than others in the class.

In conclusion, this unit was "OK" and I hope I do well in the first test as well as everyone else. With that said, goodluck to everyone!

PS..were we taught the graph for tangent when I wasn't here? Because in excercise 6, I believe there is a question about it and I didn't know how to do it?! Help?

#### 1 comment:

m@rk said...

Roxanne,

If you want to see the graph of the tangent function, you can go right ahead and use fooplot.com. You will see that the shape of the tangent function is somewhat different from cosine and sine.

The graph of the tangent function has some distinct properties.It has a period of pi unlike both cosine and sine which has a period of 2pi.
Second, it has a y-intercept of zero. (There are so much more to say about this function but i wont go into them, because i don't want to spoil the fun).

Graphing the tangent function follows the same rule as graphing both cosine and sine functions. The general equation for the tangent function is f(x) = a*tan(bx+c)+d. You can see that it uses the same parameters.All the parameters work the same way as the one in the sine and cosine equations. It also follows the same algorithm DABC (but i prefer using BCDA).

I hope this helps you clarify things.

-m@rk