Tuesday, December 11, 2007

Parabolas

0kay so here is my scribe, call me old fashion but the Smartboard Software didn't download properly on my computer. Sorry for the late, late post. On Monday, we learned about parabolas and looked deeper into what they are. In the beginning of class Mr.K told everyone to take a piece of paper and gave us instructions on how to fold it. When we were all done you could see parabolas on the paper from the indents from folding. We continued on learning about the Focus point, "P", "p", the vertex and etc.


0kay for around an hour or so i've been attempting to upload pictures that i drew on paint and it hasn't been working at all. It says it's loading but it never completes the process. I have tried uploading the slides as well, I restarted my computer but it still didn't help so I'm going to tried to explain without any pictures...

This is the standard form of a parabola:

(x-h)^2=4p(y-k)

PARABOLA: the locus, of points, obey a certain rule to make a parabola.
LOCUS: set of points.


****When you want to identify whether the parabola is horizontal or vertical you need to recognize if "x" or "y" is being squared. If "x" is being squared then vertical but if "y" is being squared then you know it's horizontal.****

****To determine if the parabola is opening upwards or downwards, or which side it's opening towards, you look at "p" and if it's positive it will open to the positive side (upwards). If it's negative it will open to the negative side(downwards).****

****Where's the vertex??? The vertex is found by taking "h" & "k" and multiplying them by -1 because in the standard form "h" & "k" have negative signs. Now you have both "x" and "y" coordinates for your vertex, x=h and y=k.****

****Directrix??? This is a line that the parabola must have to be an actual parabola. It is the line that is either an x coordinate or y coordinate, it IS NOT an order pair!

DISTANCE FROM FOCUS POINT TO VERTEX = DISTANCE FROM VERTEX TO DIRECTRIX

DISTANCE FROM ANY POINT ON THE PARABOLA TO DIRECTRIX = DISTANCE FROM ANY POINT ON THE PARABOLA TO THE FOCUS POINT

These notes are a couple of notes i took down in class on Monday, we spent a lot of time understanding these important facts and discussing the "folding paper" experiment. Sorry for the short blog hopefully it's helpful. If there are any questions comment below or corrections of any kind. Thanksss. :) Next scribe is
Sergio, he will being doing today's.

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