Find the area of the region bounded by the curve y=2x-x2 and the straight line y=-x.

Given the boundaries of the area O befound are,


• Curve is y = 2x – x2


• Line y = -x


Consider the curve


y = 2x – x2


x2 -2x = - y


adding 1 on both sides


x2 – 2x +1 = -(y-1)


(x-1)2 = -(y-1)


This clearly shows, the curve is a parabola with vertex B (1,1)


Consider the curve, y = 2x – x2 and substitute the line -x = y in the curve


-x = 2x – x2


x2 – 2x – x = 0


x2 – 3x = 0


x(x-3) = 0


x = 3 (or) x = 0


substituting x in y = -x


y = -3 (or) y = 0


So , the parabola meets the line y = -x at 2 points, A (3,-3) and •(0,0)



As per the given boundaries,


• The parabola y = 2x - x2, with vertex at B(1,1).


• Line y = -x


The boundaries of the region to be found are,


Point A, where the curve y = 2x - x2 and the line y = -x meet i.e. A (3,-3)


Point B, where the curve y = 2x - x2 has the extreme end the vertex i.e. B (1,1)


Point C, where the curve y = 2x - x2 and the line y= -x meet i.e. C (2,0)


Point O, the origin


Area of the required region = Area of OACBO


Area of OACBO= Area under OBCA – Area under line OA






[Using the formula ]




The Area of the required region


1