# Finding The Equidistant of 2 Points

1. Oct 18, 2009

### Ecom

1. The problem statement, all variables and given/known data

I need the formula for finding the coordinates of the point on the y axis that are equildistant from two other pair of points (3,0) and
(3,6).

2. Relevant equations
i don't know, but these might have something to do with it.

$$\sqrt{}$$ (y2-y1)2+(x2-x1)2

(x2+x1$$/$$2, y2+y1$$/2$$)

3. The attempt at a solution
I found the midpoint of (3,0)-(3,6), and found the distance between the midpoint to the endpoints, but i don't know were to got from there. I also tried writing random scribbles on my graph papers, crying, begging God to take me out of IB extended math, and finally, posting on Physics Forums for help.

Last edited: Oct 18, 2009
2. Oct 18, 2009

### LCKurtz

Hint: Points equidistant from your two points would be on the perpendicular bisector of the line joining them. Draw a sketch.

3. Oct 18, 2009

### Ecom

Ah Yes, but that would be too easy! I need to find the anwser using an equation.

4. Oct 18, 2009

### LCKurtz

Sure. Solve for the mid-point between your points. Write the equation of the perpendicular bisector. Solve for where it hits the y axis. The picture was just to lead the way.

5. Oct 18, 2009

### Ecom

ohhhhhhhhhhh......

Probably should have looked up "perpendicular bisector". I knew what perpendicular meant, but you threw me off at bisector.

Anyway, thanks for the information. Saved me hours of going over "attempt at solution" again

6. Oct 19, 2009

### HallsofIvy

Staff Emeritus
This is particularly simple because it is a vertical line. Any line perpendicular to it is a horizontal line and has the equation "y= constant". But the problem is finding that constant. To do that you need to know the y-component of the midpoint, which was what the original question asked!

It should be obvious what the x-component is. What point is half way between 0 and 6 on the number line?