# Closest point on line to two points...

• Nov 29th 2009, 04:20 PM
PJani
Closest point on line to two points...
Hy im having problem solving one problem with derivates i think.

I have two points and im looking for closest summed distance point on line.

two points are T1(-1, 2) and T2(1,6) and line is very simple y = x.
• Nov 29th 2009, 04:27 PM
skeeter
Quote:

Originally Posted by PJani
Hy im having problem solving one problem with derivates i think.

I have two points and im looking for closest summed distance point on line.

two points are T1(-1, 2) and T2(1,6) and line is very simple y = x.

since $y = x$ ...

$d = \sqrt{(x+1)^2 + (x-2)^2} + \sqrt{(x-1)^2 + (x-6)^2}$
• Nov 29th 2009, 05:15 PM
PJani
Quote:

Originally Posted by skeeter
since $y = x$ ...

$d = \sqrt{(x+1)^2 + (x-2)^2} + \sqrt{(x-1)^2 + (x-6)^2}$

Thank you (Rofl)it helped...what about other more extended functions y = k*x +n?
• Nov 29th 2009, 05:33 PM
skeeter
Quote:

Originally Posted by PJani
Thank you (Rofl)it helped...what about other more extended functions y = k*x +n?