Using integration, find the area of the region in the first quadrant, enclosed by the x-axis, the line y=x and the circle x2+y2=32

Given the boundaries of the area to be found are,


• the circle, x2 + y2 = 32 ---(1)


• the line, y = x---- (2)


• Area should be in first quadrant.


From the equation, of the first circle, x2 + y2 = 32


• the vertex at (0,0) i.e. the origin


• the radius is 4√2 unit.


Now to find the point of intersection of (1) and (2), substitute y = x in (1)


x2 + x2 = 32


2x2 = 32


x2 = 16


x = ± 4


Substituting x in (2), we get y = ± 4


So the two points, A and B where (1) and (2) meet are A = (4,4) and B = (-4,-4)



As x and y have even powers for both the circles, they will be symmetrical about the x-axis and y-axis.


Consider the circle, x2 + y2 = 32, can be re-written as



----- (3)


Let us drop a perpendicular from A on to x-axis. The base of the perpendicular is C = (4, 0)


Now, the area to be found will be the area is


Area of the required region = Area of OADO.


Area of OADO= Area of OAC•+ Area of CADC


Area of OADOis




[Using the formula, and ]




[sin-1(1) = 90° and ]



= 4π


Area of the required region is 4π sq. units.


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