1. SLOPE-INTERCEPT FUNCTIONS ALGEBRA 1

2. DO YOU REMEMBER? Ordered Pairs? Two-Dimensional Graphs? Functions? Plotting Points? Domain and Range? Single-Variable Equations?

3. WHAT IS SLOPE-INTERCEPT FORM?  Slope-Intercept form is a Function  Slope-Intercept form has two variables  Slope-Intercept form is for a straight line  Slope-Intercept form is in Two Dimensions  Slope-Intercept form has four parts

4. SLOPE-INTERCEPT EQUATION Y = mX + b The number you plug in (variable) The number you get out (variable) The slope of the function (constant) The Y-intercept of the function (constant)

5. SLOPE AND Y-INTERCEPT Slope is the difference between two ordered pairs (y2-y1) (x2-x1) Y1 and x1 are the first ordered pair (x1,y1) Y2 and x2 are the second ordered pair (x2,y2) Y-intercept is the place where the line crosses the Y-axis Y = mX + b When X = 0, then Y = b (0,b) m =

6. SLOPE-INTERCEPT EQUATION (0,3) (3,1) X, 0 and 3 Y, 3 and 1 (1-3)(1-3) (3-0) m = -2/3 b = 3 m = 2 3 Slope-Intercept Form Y = -(2/3)X + 3

7. USING SLOPE-INTERCEPT FUNCTIONS You select a whole number You plug it into the equation for X You solve the equation with the number you plugged in You write the number you get down with the other number as an ordered pair You plot the ordered pair onto a graph

8. SLOPE-INTERCEPT EQUATION (0,3) (3,1) 2 3 Slope-Intercept Form Y = -(2/3)X + 3 (-3,5) (2, 1.67) (6,-1) 3 2 03 31 -35 XY 6 2-1.67

9. IN CONCLUSION… Slope-Intercept Form is for a straight line The equation is Y = mX + b m is the slope; b is the y-intercept You plug in a point for X and get a Y The numbers for X and Y are an ordered pair