JEE Main · Mathematics → Steady

Application of Integrals appeared 27 times across 3 years — 3.1% of Mathematics. This question is from Area Under Curves.

Year 2026 2025 2024 Total
Questions 9 11 7 27

Let the area of the region (x,y):0≤ x≤ 3,0≤ y≤ x² +2,2x + 2 be A. Then 12A is equal to

Numerical Answer Type:
Enter a numerical value Answer: 164 to 164 +4 marks

Solution & Explanation

Related Formula
Area A = ∫ f(x), g(x) dx
Core Logic

Let us find the point of intersection of the curves y = x² + 2 and y = 2x + 2:

x² + 2 = 2x + 2 x² - 2x = 0 x = 0 or x = 2

Evaluating behaviors over boundaries:

  • For 0 ≤ x ≤ 2: x² + 2 ≤ 2x + 2 = x² + 2
  • For 2 ≤ x ≤ 3: 2x + 2 ≤ x² + 2 = 2x + 2
Step 1: Integration Resolution

Setting up continuous area integral steps:

A = ∫₀² (x² + 2) dx + ∫₂³ (2x + 2) dx A = [ (x³)/(3) + 2x ]₀² + [ x² + 2x ]₂³ A = ( (8)/(3) + 4 ) + ( (9 + 6) - (4 + 4) ) A = (20)/(3) + (15 - 8) = (20)/(3) + 7 = (41)/(3)

Area Under Curves diagram for Q25 - JEE Main 2024 Evening
Area Under Curves diagram for Q25 - JEE Main 2024 Evening

Step 2: Scaling the Output Value

We need to compute 12A:

12A = 12 × (41)/(3) = 4 × 41 = 164
Pattern Recognition

For min/max boundary sets, always compute intersections first to accurately split integration domains into separate regions.

Chapter Mix

Class 12 Mathematics: Application of Integrals

More Application of Integrals Previous-Year Questions — Page 6

Q11 jee_main_2024_31_jan_evening Area Under Curves
The area of the region enclosed by the parabola y = 4x - x² and 3y = (x - 4)² is equal to
  • A. (32)/(9)
  • B. 4
  • C. 6
  • D. (14)/(3)

Solution

Related Formula
Area = ∫ₐb (yupper - ylower) dx
Core Logic

Area Under Curves diagram for Q11 - JEE Main 2024 Evening
Area Under Curves diagram for Q11 - JEE Main 2024 Evening

Find intersection points of y = 4x - x² and 3y = (x - 4)²:

3(4x - x²) = x² - 8x + 16 12x - 3x² = x² - 8x + 16 4x² - 20x + 16 = 0 x² - 5x + 4 = 0

Roots are x = 1, 4.

Area integral:

Area = ∫₁⁴ [ (4x - x²) - ((x - 4)²)/(3) ] dx = [ (4x²)/(2) - (x³)/(3) - ((x - 4)³)/(9) ]₁⁴ = [ 2(16) - (64)/(3) - 0 ] - [ 2(1) - (1)/(3) - ((-3)³)/(9) ] = ( 32 - (64)/(3) ) - ( 2 - (1)/(3) + 3 ) = (32)/(3) - ( 5 - (1)/(3) ) = (32)/(3) - (14)/(3) = (18)/(3) = 6
Chapter Mix

Class 12 Maths: Applications of the Integrals

Q5 jee_main_2024_31_jan_morning Area bounded by Parabolas and Inequalities
The area of the region (x,y): y² ≤ 4x, x < 4, (xy(x - 1)(x - 2))/((x - 3)(x - 4)) > 0, x ≠ 3 is
  • A. (16)/(3)
  • B. (64)/(3)
  • C. (8)/(3)
  • D. (32)/(3)

Solution

Core Logic

Given y² ≤ 4x and x < 4. Analyze the inequality (xy(x-1)(x-2))/((x-3)(x-4)) > 0 considering y > 0 and y < 0 separately.

Area bounded by Parabolas and Inequalities diagram for Q5 - JEE Main 2024 Morning
Area bounded by Parabolas and Inequalities diagram for Q5 - JEE Main 2024 Morning

Step 1: Case I (y > 0)

If y > 0, the inequality reduces to (x(x-1)(x-2))/((x-3)(x-4)) > 0. Using wavy curve method and given x in (0, 4): x in (0, 1) (2, 3).

Step 2: Case II (y < 0)

If y < 0, the inequality reduces to (x(x-1)(x-2))/((x-3)(x-4)) < 0. Using wavy curve method and given x in (0, 4): x in (1, 2) (3, 4).

Step 3: Area Computation

Because the regions map perfectly without overlap in opposite quadrants relative to the x-axis, they form complete parabolic strips when combined: Area = 2 ∫₀⁴ √(x) dx = 2 · (2)/(3)[x3/2]₀⁴ = (4)/(3) · 8 = (32)/(3).

Chapter Mix

Class 12 Maths: Area Under Curves Class 11 Maths: Linear Inequalities

Rankbit System
JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%) | JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%)