If the solution of the differential equation
dydx=1xcosy+sin2y is x=cesiny-k(1+siny), then the value of k is
dydx=1xcosy+2sinycosy∴dxdy=xcosy+2sinycosydxdy+−cosyx=2sinycosyI.F.=e−∫cosy dx=e−siny∴ the solution is x.e−siny=2∫e−siny siny cosy dy=−2sinye−siny+2∫e−sinycosydy=−2sinye−siny−2e−siny+c⇒x=−2siny−2+cesiny=cesiny−21+siny+c∴k=2