## Book: RD Sharma - Mathematics (Volume 2)

### Chapter: 21. Areas of Bounded Regions

#### Subject: Maths - Class 12th

##### Q. No. 15 of Exercise 21.3

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15
##### Draw a rough sketch and find the area of the region bounded by the two parabolas y2 = 4x and x2 = 4y by using methods of integration.

To find the area bounded by

y2 = 4x

...(i)

And x2 = 4y

...(ii)

On solving the equation (i) and (ii),

= 4x

Or, x4 – 64x = 0

Or, x(x3 – 64) = 0

Or, x = 0, 4

Then y = 0,4

Equation (i) represents a parabola with vertex (0,0) and axis as x – axis. Equation (ii) represents a parabola with vertex (0,0) and axis as y - axis.

Points of intersection of the parabola are (0,0) and (4,4).

A rough sketch is given as: -

Now the bounded area is the required area to be calculated, Hence,

Bounded Area, A = [Area between the curve (i) and x axis from 0 to 4] – [Area between the curve (ii) and x axis from 0 to 4]

On integrating the above definite integration,

Area of the region bounded by the parabolasy2 = 4x and x2 = 4y is sq. units.

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