graphing equations of lines using x- and y-intercepts
TRANSCRIPT
Graphing Equations of LinesUsing x- and y-Intercepts
Find the x-intercept• The x-intercept is the point where the graph of the
equation crosses the x-axis. • The coordinate will be (x, 0) where the x will be the
point on the x-axis where it crosses. • To find the x-intercept of an equation, substitute the
value of 0 into the equation for the y value. Example:
0
2 3 12
2 3( ) 12
2 12
6
x y
x
x
x
By substituting 0 for y in the equation, we find the x-intercept which is (6,0). This becomes your first point on the graph.
Find the y-intercept• The y-intercept is the point where the graph of the
equation crosses the y-axis. • The coordinate will be (0, y) where the y will be the
point on the y-axis where it crosses. • To find the y-intercept of an equation, substitute the
value of 0 into the equation for the x value. Example:
2 3 12
2( ) 3 12
3
0
12
4
x y
y
y
y
By substituting 0 for x into the equation, we find the y-intercept which is (0,4). This becomes your second point on the graph.
The Graph2x+3y=12
Series 1
-8 -6 -4 -2 2 4 6 8
-8
-6
-4
-2
2
4
6
8
x
y
(6,0)
(0,4)
We found the point (6,0) for the x-intercept and (0,4) for the y-intercept. When graphing equations of lines, this method works for every graph.
Remember
To find the x-intercept, let the value of y equal 0 in the equation.
To find the y-intercept, let the value of x equal 0 in the equation.