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

Year 2026 2025 2024 Total
Questions 13 17 16 46

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

Solution & Explanation

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

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