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Application of Integrals appeared 27 times across 3 years — 3.1% of Mathematics. This question is from Area Bounded by Parabolas and Lines.

Year 2026 2025 2024 Total
Questions 9 11 7 27

Let P₁: y = 4x² and P₂: y = x² + 27 be two parabolas. If the area of the bounded region enclosed between P₁ and P₂ is six times the area of the bounded region enclosed between the line y = α x, α > 0 and P₁, then α is equal to:

Solution & Explanation

Related Formula

Area enclosed by y = f(x) and y = g(x) from x=a to x=b:

A = ∫ₐ^b |f(x) - g(x)| dx

Area between x² = 4ay and line x = my is (8a²)/(3m³).

Core Logic

Find Points of Intersection for P₁ and P₂:

4x² = x² + 27 ⇒ 3x² = 27 ⇒ x = ± 3

Parabolas intersection bounds
Parabolas intersection bounds

Area bounded between P₁ and P₂:

A₁ = ∫₋₃³ ((x² + 27) - 4x²) dx = 2 ∫₀³ (27 - 3x²) dx A₁ = 2 [27x - x³]₀³ = 2(81 - 27) = 108 sq. units
Execution

Area between P₁ and y = α x is given as 108 / 6 = 18 sq. units. For x² = 4ay and x = my, area is (8a²)/(3m³). Here, the parabola is x² = (y)/(4) and line is x = (y)/(α). Thus, 4a = (1)/(4) ⇒ a = (1)/(16), and m = (1)/(α).

Parabolas intersection bounds
Parabolas intersection bounds

Applying the formula:

(8(1/16)²)/(3(1/α)³) = 18 (8 / 256)/(3 / α³) = 18 ⇒ (α³)/(96) = 18 α³ = 18 × 96 = 1728

α = 12

Pattern Recognition

Using the standard result (8a²)/(3m³) for the area bounded between x²=4ay and x=my avoids tedious integration for straight lines intersecting parabolas at the origin.

Chapter Mix

Class 12 Maths: Application of Integrals

Reference Study Guides

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

More Application of Integrals Questions — jee_main_2026_28_january_evening

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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%)