JEE Main 2022 · 28 July · Morning Shift · Mathematics · Differential Equations
If y = y(x) , x ∈ (0, (π)/(2)) be the solution curve of the...
If y=y(x), x \in \left(0, \dfrac{\pi}{2}\right)be the solution curve of the differential equation</p><p>\left(\sin^{2}2x\right)\dfrac{dy}{dx} + \left(8sin22x + 2\sin 4x\right)y=
2e−4x(2sin2x+cos2x),withy\left(\dfrac{\pi}{4}\right)=e−π, then y(6π) is equal to
Options
A32e−32π
B32e32π
C31e−32π
D31e32π
Correct answer
A. 32e−32π
Step-by-step solution
Given, (sin22x)dxdy+(8sin22x+2sin4x)y=
2e−4x(2sin2x+cos2x)
Now rewriting the given differential equation we get,
⇒dxdy+(8+4cot2x)y=sin22x2e−4x(2sinx+cos2x)
Which is a linear differential equation.
Now calculating IF=e∫(8+4cot2x)dx=e8x+2ln(sin2x)
=e8x⋅sin22x
Now solution of differential equation is given by,
y×IF=∫sin22x2e−4x(2sin2x+cos2x)×IFdx
⇒y(e8x⋅sin22x)=∫2e4x(2sin2x+cos2x)dx
⇒y(e8x⋅sin22x)=e4x⋅sin2x+C
Now given y(4π)=e−π⇒C=0
So, the equation of curve is given by y=sin2xe−4x
So, the value of y(6π)=sin(2⋅6π)e−46π=32e−32π