A line through the origin

The equation of a line through the origin:

ax+by=0

A sample:

You can drag the red dot to change the slope of the line, that is, influence a and b. The vector pointing to the red dot represents the direction vector.

Change the value of x by dragging the slider:

-60-40-200204060-60-40-200204060p-40.030.050.066.7

A line at a distance from the origin

The equation of a line through the origin:

ax+by=c

A sample:

You can drag the red dot to change the slope of the line, that is, influence a and b. The vector pointing to the red dot represents the direction vector. The length of this vector influences c.

Change the value of x by dragging the slider:

-60-40-200204060-60-40-200204060p50.055.0