Download Slope-Intercept Form Point-Slope Form Special Case Horizontal

Slope-Intercept Form
y = mx + b
Point-Slope Form
y − y1 = m (x − x1 )
Clues about when to use different formulas
Wednesday October 21, 2015
Clues about Horizontal and Vertical Lines
Special Case
Horizontal Lines
Special Case
Vertical Lines
Horizontal Lines
The slope of all horizontal lines is zero.
m=0
(‐3,2) (0,2) (2,2) Vertical Lines
The slope of all vertical lines is undefined.
m = undefined
(2,3)
(2,0) When can I use this formula immediately?
Example: Write an equation of a line that has a slope of − 12
and a y-intercept of ( 0, 12 )
When can I use this formula immediately?
Example: Write an equation for the line that passes
through the point ( −5,3) and that has a slope of 75 .
What do I sometimes have to do after writing it in
point-slope form?
What would the directions say to make me do this?