In the given figure OB is perpendicular bisector of the line segment DE. FA perpendicular OB and OF intersects OB at the point C. Then prove that 1/OA+1/OB=2/OC

In the given figure OB is perpendicular bisector of the line segment DE. FA perpendicular OB and OF intersects OB at the point C. Then prove that 1/OA+1/OB=2/OC