Thursday, February 15, 2007
2/15 Pre Algebra - Writing Equations Of Lines
Today students will continue their work with linear equations and graphs. In this lesson, we will not be graphing, but we will use graphs to determine the equation of a line. Students will be given one of three scenarios:
1) A slope and a y-intercept
2) A graph with two points labeled
3) The equation of a parallel or perpendicular line and the y-intercept
They will use this information to write the equation of a line. To see an example of how to do the first scenario, click on the video above. To see some explanations of the second 2 scenarios, click here.
The students took notes over some example problems, then we did a worksheet together in class for practice and finally they were allowed to work on their graded assignment due for Monday.
Homework:
pages 422-423 #'s 8-23 all
Subscribe to:
Post Comments (Atom)
8 comments:
so if we plug 0 in for X in something like this Y=2x+3 would we multiply the intercepts?
Thanks for the question Brian....
If you plug 0 in for x in y=2x+3, you would have y=2(0)+3 or y=3. That is the y-intercept.
I thought the lesson was pretty easy! After I asked some questions, I knew how to do it exactly!
Thanks for the comment James. It seemed to me that you understood what you were doing from the quesitons you were asking. Keep up the good work. Thanks for commenting.
I don't get the thing with the perpendicular and parrallel questions.
Travis-
Thanks for the question. If you can remember 2 things, it should be easy.
1) parallel lines have equal slopes
2) perpendicular lines have negative reciprocal slopes (flip the fraction and change its sign)
Example) A slope parallel to 1/2 is 1/2. A slope perpendicular to 1/2 is -2/1.
Hope that helps!
little confused with the (6,4)&(15,4)
Aimee-
Thanks for the question. To find the slope, you will be subtracting the y's on top. This will give you 4-4, which is 0. Anytime you have 0 on the top, the slope is 0. Hope this helps!
Post a Comment