Math 105
Sec. 1-2 Review of Lines:
Two points determine a line in the plane.
Lines have constant slope.
From the graph of a line you should be able to determine an
equation of the line.
From an equation of a line, you should be able to sketch its
graph.
Given either a careful graph or an equation of a line, you
should be able to:
oDetermine its slope
oFind points on a line (& determine if a point isn’t on the line)
oFind the x and y intercepts
Given 2 points or the slope and one point, you should be
able to get an equation of the line and its graph.
The x-intercept is the point where y=0.
The y-intercept is the point where x=0
You should be able to look at a graph of a line and
immediately tell if the slope is positive, negative, zero or
undefined.
You should be able to look at an equation and immediately
tell if its graph is a line or not.
Parallel lines have the same slope.
The slopes of perpendicular lines are opposite reciprocals.