Mathematics · Area under the Curves

JEE Main 2024 — 4 April, Shift 2 — Question 9

The area (in sq. units) of the region described by {(x,y):y2≤2x\left\{(\mathrm{x}, \mathrm{y}): \mathrm{y}^{2} \leq 2 \mathrm{x}\right., and y≥4x−1}\left.\mathrm{y} \geq 4 \mathrm{x}-1\right\} is

  1. Option A:

    1132\frac{11}{32}

  2. Option B:

    89\frac{8}{9}

  3. Option C:

    1112\frac{11}{12}

  4. Option D:

    932\frac{9}{32}

    Correct

Answer: D

Step-by-step solution

Shaded area =∫−121(xRight −xLeft )dy=\int_{-\frac{1}{2}}^{1}\left(\mathrm{x}_{\text {Right }}-\mathrm{x}_{\text {Left }}\right) \mathrm{dy}

y2=2xy^{2}=2 x

y=4x−1y=4 x-1

y=1,y=−12y=1, y=-\frac{1}{2}

shaded area =∫−121(y+14−y22)dy=\int_{-\frac{1}{2}}^{1}\left(\frac{y+1}{4}-\frac{y^{2}}{2}\right) d y

=(14(y22+y)−y36)−121=932=\left(\frac{1}{4}\left(\frac{y^{2}}{2}+y\right)-\frac{y^{3}}{6}\right)_{-\frac{1}{2}}^{1}=\frac{9}{32}

Solution figure

Answer key and solution verified before publishing.

Practise Area under the Curves

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.

Exam
JEE Main 2024
Subject
Mathematics
Chapter
Area under the Curves
Topic
Area under the Curves