1. Lesson 3-6/3-7: More Equations of Lines (parallel and perpendicular) Objective Students will: Write equations given two points State the slope and y-intercept from an equation Graph linear equations Find the standard form of equations

2. Remember equations like Ax + By =C are called standard form. (no fractions and A is positive) The slope is given as m =. Why????

3. Example 2: Write the equation of the line (in slope-intercept form) through (3,1) and (5, 7) 2 choices a) point-slope or b) slope intercept Both require SLOPE!!!!!! Which we do not have!!!! Find the slope m= Which formula do we need? (Make sure to pick only one point to substitute!!!)

5. Ex 5: Find the equation of the line with points at (2,4) and (0,6)

6. Graph the following lines y = 2x + 1 2x – y = 3 What do you notice about the slopes? What do you notice about the lines?

7. What do you notice about the slopes? What do you notice about the lines?

8. Look at the slopes from the graphs: Parallel lines → same slope Perpendicular line → “opposite reciprocal” slope Writing Equations 1)Get the slope you want 2)Plug it to point-slope then solve for y (slope-intercept) Remember: In standard form the slope is

9. Example 3: Write an equation in standard form for a line perpendicular to 3x + 4y = 5 through (3, -2) What slope is this line? What slope will you use? Use point-slope then rearrange to Standard Form.

10. Example 2: Write an equation for a line containing (1, 3) parallel to the line containing (2,5),(-3,8) What slope do we have? What slope will we use? Use point-slope then rearrange to slope-intercept!!

11. Assignment 3-6/136-137/ 1-11o, 13-33 eoo (graph all), 37-51o