JEE Main202430 Jan 2024Morning ShiftMathematicsDifferential EquationsActual
Let y = y ( x ) be the solution of the differential equation sec x d y + 2 1 - x tan x + x 2 - x d x = 0 such that y 0 = 2 . Then y 2 is equal to :
Options
- A2
- B2 1 - sin ( 2 )
- C2 sin ( 2 ) + 1
- D1
Correct answer
A. 2
Step-by-step solution
Given: sec x d y + 2 1 - x tan x + x 2 - x d x = 0 ⇒ sec x d y = 2 x - 1 tan x + x 2 - 2 x d x ⇒ d y cos x = 2 x - 1 sin x cos x + x 2 - 2 x d x ⇒ d y = 2 x - 1 sin x + x 2 - 2 x cos x d x ⇒ ∫ d y = ∫ 2 x - 1 sin x + x 2 - 2 x cos x d x ⇒ ∫ d y = ∫ 2 x - 1 sin x + ∫ x 2 - 2 x cos x d x ⇒ y ( x ) = ∫ 2 ( x - 1 ) sin x d x + x 2 - 2 x ( sin x ) - ∫ ( 2 x - 2 ) sin x d x ⇒ y ( x ) = x 2 - 2 x sin x + λ It is given that, y 0 = 2 ⇒ y ( 0 ) = 0 - 0 sin 0 + λ ⇒ 2 = 0 + λ ⇒ λ = 2 ⇒ y ( x ) = x 2 - 2 x sin x + 2 ⇒ y ( 2 ) =