1. Algebra 1 6 Dec 2011 1) Put papers from your group folder into your binder. 2) Put your binder, hw and text on your desk. START WU. ONLY weekly WU and daily CW in folder. CHECK YOUR HOMEWORK √ or X each problem WARM UP- Solve and check 1) 2x – 5 = 12 2) 2(x – 5) = 20 3) 4x + 5x + 6 = 24 4) 3 – 2(x+3) = 9

2. Objective Students will be create and interpret a scatter plot and find the equation of the line of fit. Students will take notes and use think-pair-share.

3. homework due today pg. 244: 1, 2, 3 homework due next class finish your scatter plot ½ sheet both sides STUDY for QUIZ on finding equations

4. finding equations 1. WHERE does it START? (y value when x = 0) 2. INCREASING OR DECREASING? 3. BY HOW MUCH EACH TIME? Slope!!

5. review- how can you find slope? Look in your yellow page notes. 1) how do you find slope using a slope triangle? 2) slope from a table? 3) what is the slope triangle?

6. slope using a slope triangle over 5 down 20 1. pick two GOOD points 2. Draw one horizontal arrow and one vertical angle to connect the two points to make a TRIANGLE 3. Count the spaces- remember SCALE!! SLOPE =

7. equation from 2 points-- use a table example: find the slope between (4,12) and (6,16) xy 412 616 +2 +4 xy 412 616 1. Put the points in a table 2. find the differences in x and y values SLOPE = 4. extend table to find y-intercept 2 0 8 4 EQUATION y = 4 + 2x

8. (x 1, y 1 ) (x 2, y 2 ) xy x1x1 y1y1 x2x2 y2y2 (y 2 -y 1 ) (x 2 -x 1 ) y2y2 y1y1 x2x2 x1x1 slope formula Developing the slope formula y 2 -y 1 x 2 -x 1

9. find y-intercept when given two points (4, 12) and (6,16) extending the line backwards can give us an ESTIMATE…but it is EASY to be “off” and not get the exact value 1. plot the two points 2. draw your slope triangle we went up 4, over 2 (watch scale) 3. now go backwards, making slope triangles until you get to the y- intercept DOWN 4, LEFT 2 (- divide by - = +)

10. Scatter Plots 1. Scale your axises. Plot the points. 2. Draw a line of best fit. 3. Identify the y-intercept? 4. Find slope. Choose two GOOD points on your LINE (NOT necessarily FROM THE DATA TABLE) and calculate slope (make a table of points from your line and/or use a slope triangle or formula). 5. Define your variables. 6. Find the equation for your LINE : y = a + bx

11. On Penny’s 15 th birthday her grandmother gave her a large jar of quarters. Penny decided to continue saving quarters in the jar. Every few months she counts her quarters and records the number in a table. Predict how many quarters Penny will have on her 18 th birthday. 1)Make a scatter plot of the data. 2)Draw a line of best fit. Find the slope, y-intercept and an equation. 3)Predict the number of quarters she will have on her 18 th birthday. # of months 3581215192226 # of quarters 270275376420602684800830

12. Use your equation to predict Use your equation to answer questions: THINK ABOUT YOUR VARIABLES!! what does x represent? what does y stand for?

13. Handout Practice Finish for homework

14. debrief what did you learn today?