# Cartesian equations

1. Sep 16, 2004

### Przybysz

Find a cartesian equation for the perpendicular bisector of the line joining:
A, (2,3) and B, (0,6).

Haven't come across this before, and really am stuck!

2. Sep 16, 2004

### arildno

Split your problem in several subproblems:
1. What is the coordinates of the midpoint of the line segment?
2. Which unit vector is parallell to the line segment ? (That is, determine the direction vector to the line segment!)
3. Which unit vector is normal to the line segment's direction vector?
4. Construct the perpendicular by using the facts:
a) The perpendicular goes through the midpoint
b) Is parallell to the normal vector

Last edited: Sep 16, 2004
3. Sep 16, 2004

### Przybysz

I'm not so good on maths! What is a bi-sector?

4. Sep 16, 2004

### arildno

"bi-sector" bisects the line,i.e. goes through the midpoint of the line.

5. Sep 16, 2004

### mathwonk

"bi" means two, and "sect" means cut. so bisect is "cut in two".