## Tuesday, March 3, 2009

### scribe!!

Hi, its me, Aldrin B. It's my first time to scribe so i hope it'll go smoothly.

Here is today's scribe.

At the start of the class, Mr. Kuropatwa introduced an online social bookmarking website.

delicious.. was it!?
Here's a link if anyone of you guys forgot the url. (or just too lazy to type it)
http://delicious.com

It's a bookmarking service that allows users to tag, save, manage and share web pages from a centralized source. Like Mr. Kuropatwa said, instead of having different bookmarks on every computer, Delicious makes it easy to set bookmarks on every computer,

I 'm not going to discuss it briefly because i know a lot of you know how it works better than i do..

There are just few things he said we must do.

-First, you must register to this site.
(if you're still using Internet Explorer for browsing
well its up to you..XD.)
No, seriously. It has been suggested that
you use Fire fox because they say it's better, plus you need it
and its add-ons for easy tagging.

http://delicious.com/help/quicktour?tour=firefox

-Then start looking for resources related to our first and second unit the circular functions and transformation.
You have to put three tags (UNIT TITLE, YOUR NAME, and our blog name, pc40sw09)
it is due before the end of this unit.

Now let's go to our class discussion.

At the first, he gave us problems about translation and stretching.(refer to slide #2 - 03/03)

-3f ( 1/2x - 2 ) + 1

Given A ( -2 , -3 ) find the coordinates of its image under the transformation given above.

We must first reveal the true form regarding with the x axis( the ones inside the parentheses) to get how many units it really shifted.

-3f ( 1/2x - 2 ) + 1 = -3f ( 1/2 ( x - 4 ) ) + 1

After knowing that, you can now solve for the coordinates of x after transformation.

(-2) times the reciprocal of 1/2 which is 2 plus 4
(-2)(2) + 4 = 0

Focusing now on the y axis, will not be a problem because they are on the outermost of the equation.

Solving for y after transformation:

(-3)(-3) + 1 = 10

Just remember: stretching first before translation

The image of point B after the transformation shown above is ( 1 , 4 ), find the original coordinates of B.

We need to do an Inverse of the steps made above.
Solving for the x coordinate
( (1) - 4 ) / 2 = -3/2

Solving for the y coordinate

( (4) - 1 ) / -3 = -1

After that, we tackle about odd and even functions
Looking at them you can see that Odd functions if rotated 180 degrees remain the same while even functions is like functions reflected through y axis.

Testing Algebraically whether its odd or even

a function is even IFF f(-x) = f(x)
(refer to slide # 3
- 03/03)

f(x) = x^2
f(-x) = (-x)^2
f(-x) = x^2
since f(-x) = f(x)
f is an even function

a function is odd IFF f(-x) = -f(x)
(refer to slide # 4 - 03/03)

f(x) = x^3 - x
f(-x) = (-x)^3 - (-x)
f(-x) = -x^3 + x

-f(x) = -((x^3) - x)
-f(x) = -x^3 + x
since f(-x) = -f(x)
f is an odd function

I found some site which may help you understand more regarding these.

So that's it for my scribe.. I hope Its not too long or short for a scribe and did not confuse you more..
but I'm really sorry if it did. If there's any correction, feel free to tell me.

by the way.. I almost forgot about our homework...
exercise #9 num's 1 - 10.

see you guys tomorrow. have a good night everyone!!

oh..? for the next scribe.. i picked
kalekalekale! ???

#### 1 comment:

1. Heeey! (:

Just wondering, who did you pick as the next scribe?