Question 13424
For the point to bisect the line segment it must lie equ-distant from both points.


Distance from the point (a,b) = {{{((a-(a+b)/2)^2 + (b-(a+b)/2)^2)^0.5}}}

Distance from the point (b,a) =  {{{((a-(a+b)/2)^2 + (b-(a+b)/2)^2)^0.5}}}

Both distances are equal.

Hence the point ((a+b)/2,(a+b)/2) bisects the 2 given points