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The area of the region bounded by the parabola y2=xy^2 = x and the straight line 2y=x2y = x is

Solution

✅ Correct Option: 3

The area of the region bounded by the parabola y2=xy^2 = x and the straight line 2y=x2y = x.

To find where the curves intersect, from the line x=2yx = 2y.

Substituting into the parabola equation:

y2=2yy^2 = 2y

y2−2y=0y^2 - 2y = 0

y(y−2)=0y(y - 2) = 0

So y=0y = 0 or y=2y = 2

When y=0y = 0: x=2(0)=0x = 2(0) = 0 giving point (0,0)(0, 0)

When y=2y = 2: x=2(2)=4x = 2(2) = 4 giving point (4,2)(4, 2)


To determine which curve is on the right, check at y=1y = 1:

Parabola: x=y2=1x = y^2 = 1

Line: x=2y=2x = 2y = 2

Since 2>12 > 1, the line is to the right of the parabola between y=0y = 0 and y=2y = 2.


Since both equations are in terms of xx as a function of yy, integrate with respect to yy:

Area=∫02(2y−y2) dy\text{Area} = \int_0^2 (2y - y^2) \, dy

=[y2−y33]02= \left[y^2 - \frac{y^3}{3}\right]_0^2

=[(2)2−(2)33]−[0−0]= \left[(2)^2 - \frac{(2)^3}{3}\right] - \left[0 - 0\right]

=4−83= 4 - \frac{8}{3}

=123−83= \frac{12}{3} - \frac{8}{3}

=43= \frac{4}{3}

The area of the region is 43\frac{4}{3} square units.

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