1. Standard Form And Point Slope Form First, Some Important slides from last time! Take Some Notes!

2. Review: Slope-Intercept Form Slope Y-int. = Change in y = = Change in x = Slope describes a lines its steepness, incline, decline or grade.

3. calculate Slope With 2 Points we have a point (x 1, y 1 ) and another point (x 2, y 2 ) (x 1, y 1 ) (x 2, y 2 ) Change in y (rise) over the Change in x (run). It looks likes this. Review: Calculating Slope =

4. Review: Finding x-int, and y-int Remember, to find x-int, plug in 0 for y and Solve. To find y-int, plug in 0 for x. Horizontal Lines Have no x intercept, 0 slope and equal the y-intercept! Vertical Lines have no y intercept, an undefined slope and equal the x intercept!

5. Other forms of A Line Just Like there are other forms of to represent fractions, there are different ways to represent a line. Example: What are some other instances when you see things in other forms?

6. Standard Form Another way to write the equation of a line is using Standard Form. A,B and C are real numbers and A and B can not be zero.

7. Slope-Int Form to Standard Form Suppose we wanted to see the equation of a line in standard form from slope-int form. Here is what we do: Example #1 Seriously? That’s it! Dude! Piece of Cake! A = -3 B = 1 C = 4

8. Slope-Int Form to Standard Form Example #2 Seriously? That’s it! Hot Dog! Piece of Cake! A = -1/6 B = 1 C = -15

9. Standard Form to Slope-Int Form Example #3 8x + 4y = 16 -8x 4y = -8x + 16 Are we finished??? NO! /4 /4 /4 y = -2x + 4 Cereal? That’s it! Hot Dog! Easy as Pie!

10. Standard form (x- and y-int) How to find x and y int? Just plug in zero for x or y! Example #4 8x + 4y = 16 8(0) + 4y = 16 4y = 16 /4 y = 4 8x + 4(0) = 16 8x = 16 /8 x = 2 Find y-int, plug in zero for x! Find x-int, plug in zero for y! Wowsers!

11. Point-Slope Form The last form we will look at is Point-Slope Form. The hole point (Get it) of this form is an easy way to write an equation for a line using the slope, and a point (Hence the name!). The Form is….. Drum Roll Tap those fingers on your desk!

12. Point-Slope Form Let us see how we make an equation using Point-Slope Form. Given that Slope equals 3 and a point (2,4), write an equation of a line using point-slope form. What do we do? We have m and x 1,y 1.. so.. Plug and Chug! An you leave it!

13. One mo Time… Slope equals -6 and a point (-2,-4), write an equation of a line using point-slope form. Plug and Chug! No Way, Really? That is Simple!

14. Point Slope Form to Standard and Slope-int We gotta do it, so lets try it out for this equation. First standard Form -20 -7x Time out! It’s Slope-int! It’s Standard! Wow we WOW WOW! Let’s keep on truckin’

15. Last Example using 2 points! Using (3,-6) and (-5,2), find the equation of the line using point-slope form. We need to find m Wait a minute, We’ve Done This!!

16. Last Example using 2 points! Using (3,-6) and (-5,2), find the equation of the line using point-slope form. m = -1 So lets plug and chug, but which points? They both work!!! (3,-6)(-5,2) They Look Different, But They describe the same Line. Don’t Believe me? Find the x and y-int!!