1) Slope of a vertical line = Undefined
This is because a vertical line does not have a change in the x - axis, that is,
△x = 0
Slope = △y / △x
Slope = △y / 0
Slope = Undefined.
2) The slopes of parallel lines are the equal.
When two lines are parallel, they have equal slope.
3) The product of the slopes of two perpendicular lines equals -1
This means that two perpendicular lines have slopes that are negative reciprocals of each other
4) The slope - Intercept relation of the equaltion of a line is:
y = mx + c
The y - intercept, c = 3
slope, m = 4
y = 4x + 3
5) The standard form for a linear equation is:
Ax + By = C
where A, B, and C are constants.