Mathematics · Area under the Curves

JEE Main 2024 — 27 January, Shift 1 — Question 22

Let the area of the region {(x,y):x−2y+4≥0\{(x, y): x-2 y+4 \geq 0, x+2y2≥0,x+4y2≤8,y≥0}\left.x+2 y^{2} \geq 0, x+4 y^{2} \leq 8, y \geq 0\right\} be mn\frac{m}{n}, where mm and n are coprime numbers. Then m+n\mathrm{m}+\mathrm{n} is equal to

Answer: 119

Numerical answer — enter this value.

Step-by-step solution

A=∫01[(8−4y2)−(−2y2)]dy+A=\int_{0}^{1}\left[\left(8-4 y^{2}\right)-\left(-2 y^{2}\right)\right] d y+

∫13/2[(8−4y2)−(2y−4)]dy\int_{1}^{3 / 2}\left[\left(8-4 y^{2}\right)-(2 y-4)\right] d y

=[8y−2y33]01+[12y−y2−4y33]13/2=10712=mn=\left[8 y-\frac{2 y^{3}}{3}\right]_{0}^{1}+\left[12 y-y^{2}-\frac{4 y^{3}}{3}\right]_{1}^{3 / 2}=\frac{107}{12}=\frac{m}{n}

∴m+n=119\therefore \mathrm{m}+\mathrm{n}=119

Solution figure

Answer key and solution verified before publishing.

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