β
MEMORIZE
- Ordered pair: (x, y) β x is horizontal, y is vertical
- Slope: rise Γ· run = (yββyβ) Γ· (xββxβ)
- Slope-intercept form: y = mx + b (m = slope, b = y-intercept)
- Origin = (0, 0); Quadrants IβIV labeled counter-clockwise
Slope m = (yβ β yβ) / (xβ β xβ)
y = mx + b
Quadrant I: (+, +) II: (β, +)
Quadrant III: (β, β) IV: (+, β)
EXAMPLE
Slope between (1, 2) and (3, 8)?
m = (8β2)/(3β1) = 6/2 = 3