Determine a distance from origin of x axis to the line that passes through the points (1;1) and (2;3).

To find the distance from origin to the line that passes
through (1,1) and (2,3) :

The line passing through (x1,y1)
and (x2,y2) is

y-y1 =
{(y2-y1)/(x2-x1)}{x-x1).

So the line through the given
points (1,1) and (2,3) is:

y-1 = {(3-1)/(2-1)}
{x-1}

y -1 = 2(x-1)

2x-y -2+1
= 0

2x-y-1 =
0.................(1).

The distance d of the line ax+by+c =
0 from the origin is given by:

d = |
c/sqrt(a^2+b^2)|

Therefore the distance of the 2x-y-1 = 0
from the origin is:

d = |-1/(sqrt(2^2+(-1)^2)| =
1/sqrt5