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Differential Equations appeared 46 times across 3 years — 5.3% of Mathematics. This question is from Homogeneous Differential Equations.

Year 2026 2025 2024 Total
Questions 13 17 16 46

If ((y)/(x)) = ₑ|x| + (α)/(2) is the solution of the differential equation x ((y)/(x))(dy)/(dx) = y ((y)/(x)) + x and y(1) = (π)/(3), then α² is equal to

Solution & Explanation

Related Formula
d((y)/(x)) = (x dy - y dx)/(x²)
Core Logic

Let us reorganize the given differential equation:

x ((y)/(x)) (dy)/(dx) - y ((y)/(x)) = x ((y)/(x)) [ x (dy)/(dx) - y ] = x

Dividing both sides by x²:

((y)/(x)) ( (x dy - y dx)/(x²) ) = (1)/(x)
Step 1: Integration Process

Let (y)/(x) = t. The equation transforms to:

t dt = (1)/(x) dx

Integrating both sides:

t = ln|x| + c ((y)/(x)) = ln|x| + c
Step 2: Resolving Constant via Boundary Limits

Given boundary state y(1) = (π)/(3):

((π/3)/(1)) = ln|1| + c √(3)2 = 0 + c c = √(3)2

Comparing with the given form ((y)/(x)) = ₑ|x| + (α)/(2):

(α)/(2) = √(3)2 α = √(3)

Therefore: α² = 3

Pattern Recognition

Recognize the standard quotient derivative pattern early. Instead of substituting y = vx mechanically, collapsing the exact differential notation directly drops layout complexities.

Chapter Mix

Class 12 Mathematics: Differential Equations

Reference Study Guides

More Differential Equations Previous-Year Questions — Page 10

Q11 jee_main_2024_31_jan_morning Linear Differential Equations
Let y = y(x) be the solution of the differential equation (dy)/(dx) = (( x) + y)/( x( x - x x)), x in (0, (π)/(2)) satisfying the condition y((π)/(4)) = 2. Then, y((π)/(3)) is
  • A. √(3)(2 + ₑ√(3))
  • B. √(3)2(2 + ₑ 3)
  • C. √(3)(1 + 2 ₑ 3)
  • D. √(3)(2 + ₑ 3)

Solution

Core Logic
(dy)/(dx) = (( x)/( x) + y)/( x ((1)/( x) - ( ² x)/( x))) = ( x + y x)/( x (1 - ² x)) (dy)/(dx) = ( x + y x)/( x ² x) = ² x + (2y)/( 2x) (dy)/(dx) - 2 (2x)y = ² x
Step 1: Integrating Factor

This is an LDE of form (dy)/(dx) + Py = Q.

I.F. = e∫ -2 (2x) dx

Let 2x = t 2dx = dt.

I.F. = e-∫ t dt = e-ln| (t/2)| = e-ln| x| = (1)/(| x|)
Step 2: Solution of LDE
y(I.F.) = ∫ Q(I.F.) dx + C y(1)/( x) = ∫ ² x (1)/( x) dx + C

Let x = t ² x dx = dt.

y(1)/( x) = ∫ (dt)/(t) + C = ln| x| + C y = x(ln| x| + C)
Step 3: Boundary Value

Given y(π/4) = 2:

2 = 1(ln 1 + C) C = 2

Thus, y = x (ln| x| + 2). At x = π/3:

y(π/3) = √(3)(ln√(3) + 2)
Chapter Mix

Class 12 Maths: Differential Equations

More Differential Equations Questions — jee_main_2024_29_january_evening

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