This is a blog for my second semester pre-calculus 30s students. Have a blast!

Wednesday, February 22, 2006

Angles in standard position, reference(related) angles, and the like.

Helloo fellow scribes ...

I am your scribe for today, and hopefully this will start the scribe program up again, and no one will get confused and mxed up again.
Today in class we learned about Angles in the standard position. We started off with this recall about quadrants: the top right section of a coordinate plain is the first quadrant. Moving counter clockwise from the first quadrant makes the top left section of the coordinate plain the second quadrant, and so on.

When the postive x axis is the first side of an angel, that is called the inital side or arm. When a ray is drawn through the origin between 0 and degrees, this ray is called the terminal side or arm. The angle that the initial and terminal sides make is called an angle in standard position.

When an angle is in standard postion:

1) it's initial side is the x axis, and the terminal side is formed by a ray extending out from the origin.
2)the angle is measured in counter clockwise direction

Consider:

Remember : r= the square root of x^2 +y^2
if (x,y) is any point on the terminal side of an angle in standard position:
The SIN of the angle is y/r
The COS of the angle is x/r
The Tan of the angle is y/x

This diagram lays out just what you have to do to find the angle you are looking for.

Remember : unknown angles are usually expressed with the greek letter theta.

Some angles have special relationships with each other. This relationship could be referred to as a Reference/related angle.

A related/reference angle is the acute angle formed between the terminal side of the angle and the nearest x axis.


We were also given a summary of reference angles, and basic facts about SINE and COSINE graphs. This I do not need to type here because I am sure you all have it. Also, there is a project due on monday, about quadratic functions, trigononmetry, and a little bit of mental math. You can work with anyone, just make sure you hand it in on monday!

Homework for tonight is Exercise #8....

If anyone has any questions, or comments, feel free to contact me. I may have made a mistake on something, so feedback is always appreciated. I am kind of in a hurry, but I hope this post does justice to all the ones that have come before it!

And the scribe for tomorrow is....Dino!

Good luck man, I know you will do well! Keep up the good work guys!

Chow.

3 Comments:

Blogger John D. - #12 said...

Good scribe post Kristin! Now I don't feel much worried about this.

7:56 PM

 
Blogger Mr. Malandrakis said...

Kristin,

Great post. This not exactly an easy lesson to scribe on, but you did an excellent job. I wouldn't expect nothing less from you. :)

Mr.M

9:18 PM

 
Blogger Richy said...

Ahhh... I remember doing that now... Hahaha. Excellent Work Kristin.

11:10 PM

 

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