Let y = y ( x ) be the solution of the differential equation, x y ' - y = x 2 ( x cos x + sin x ) , x…

Let y=y(x) be the solution of the differential equation, xy'-y=x2(xcosx+sinx),x>0. If y(π)=π, then y''π2+yπ2 is equal to :
  1. 2+π2
  2. 1+π2+π24
  3. 2+π2+π24
  4. 1+π2

Solution

Given xdydxy=x2xcos+sinx

dydx1xy=xxcosx+sinx

 I.F =e-lnx=1x

 Solution is y.1x=1x.xxcosx+sinxdx

yx=xcosx+sinxdx

yx=xsinx+C

yπ=π C=1

y=x2sinx+x

dydx=x2cosx+2xsinx+1

d2ydx2=-x2sinx+2xcosx+2sinx+2xcosx

=x2sinx+4xcosx+2sinx

 y''π2+yπ2=π24+0+2+π24+π2

=π24+2+π24+π2

=π2+2.

Asked in: JEE Main 2020 (04 Sep Shift 1)

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