For a triangle ABC, Area/R=4. Find
acosA+bcosB+ccosC.
Note:R is circumradius of triangle ABC.
(In reply to
re: Solution by Praneeth)
If we define
Area(AOB) = (R^2/2)*sin(AOB)
Area(BOC) = (R^2/2)*sin(BOC)
Area(COA) = (R^2/2)*sin(COA)
with AOB, BOC, and COA as directed angles with at least two less than 180 degrees, then this should take care of an obtuse angled triangles.

Posted by Bractals
on 20080122 15:10:46 