Slope Intercept Form Graphing Definition Intercepts The xintercept

Slope Intercept Form & Graphing

Definition - Intercepts • The x-intercept of a straight line is the x-coordinate of the point where the graph crosses the x-axis. • The y-intercept of a straight line is the y-coordinate of the point where the graph crosses the y-axis. y y-intercept x x-intercept BACK

Slope-Intercept Form y = mx + b y = 5 x + 2 BACK

Slope is Rise over Run. The numerator tells you to go up or down Positive = Up, Negative = Down. • • The denominator tells you how far to run left or right. Positive = Right, Negative = Left. BACK

Up 1, Right 3. Up 2, Left 1. Down 2 Right 3 or Up 2, Left 3 BACK

Finding the slope and intercept y- State the slope and -intercept of: y = 3 x + 2 y BACK

Up/Down Left/Right • The slope is 3 or 3/1 which means up 3 and right 1. BACK

y = 3 x + 2 y-intercept= 2 Slope = 3/1 Up 3 and Right 1 BACK

y = -2 x + 3 y-intercept= 3 Slope = -2/1 Down 2 and Right 1 BACK

y = 3 x -2 You try this one BACK

y = 3 x -2 BACK

Changing equations to the form y = mx + b • When equations are in the form ax + by = c, then you need to change them to y = mx + b BACK

Changing equations to the form y = mx + b BACK

2 x + 4 y = 8 changed to y = -1/2 x + 2 Slope = -1/2 y-intercept= 2 Down 1 Right 2 BACK

Now you change 2 x + 3 y = 6 to y = mx + b BACK

2 x + 3 y = 6 changed to y = -2/3 x + 2 BACK

Parallel Lines The equations. Same of two or parallel lines have thedifferent same slope, but two different y-intercepts.

y = 3 x + 4 and y = 3 x - 2 y = 3 x + 4 y = 3 x -2 BACK

What if there is no constant? • If you have a problem like: y = 3 x You can add a zero, “+ 0”, to the equation without changing the value. • BACK

Hints • If y = x + 3, the coefficient of x is 1, so the slope is 1/1. • If you do not have room to graph a slope of 2/1 you can use the equivalent fraction -2/-1 BACK

Slope Intercept Form & Graphing BACK