I have this equation:

$\displaystyle y'+ytanx=sinx$

The integrating factor give me $\displaystyle f=e^xcosx$

Factor replacement and give me:

$\displaystyle e^xcosxdy+e^xcosx(ytanx-senx)dx=0$ but the partial derivates give me:

$\displaystyle Q_x=cosxe^x-senxe^x$ and $\displaystyle Q_y=e^xsenx$

Thanks