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The area of the region enclosed between the curves 4x2=y4 x^{2}=y and y=4y=4 is :

Solution

✅ Correct Option: 4

First, let's find the points of intersection:

4x2=44x^2 = 4

x2=1x^2 = 1

x=±1x = \pm 1

So the curves intersect at (−1,4)(-1,4) and (1,4)(1,4).


Rearranging the parabola equation: 4x2=y4x^2=y becomes y=4x2y=4x^2


To find the area, we integrate the difference between the upper curve (y=4y=4) and lower curve (y=4x2y=4x^2) from x=−1x=-1 to x=1x=1:

Area=∫−11[4−4x2] dx\text{Area} = \int_{-1}^{1} [4 - 4x^2] \, dx

=∫−114 dx−∫−114x2 dx= \int_{-1}^{1} 4 \, dx - \int_{-1}^{1} 4x^2 \, dx

=4∫−11 dx−4∫−11x2 dx= 4 \int_{-1}^{1} \, dx - 4 \int_{-1}^{1} x^2 \, dx

=4[x]−11−4[x33]−11= 4[x]_{-1}^{1} - 4[\dfrac{x^3}{3}]_{-1}^{1}

=4(1−(−1))−4(133−(−1)33)= 4(1-(-1)) - 4(\dfrac{1^3}{3}-\dfrac{(-1)^3}{3})

=4⋅2−4(13−−13)= 4 \cdot 2 - 4(\dfrac{1}{3}-\dfrac{-1}{3})

=8−4⋅23= 8 - 4 \cdot \dfrac{2}{3}

=8−83= 8 - \dfrac{8}{3}

=24−83= \dfrac{24 - 8}{3}

=163= \dfrac{16}{3}


Therefore, the area of the region enclosed between the curves is 163\dfrac{16}{3} square units.

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