Solve y′=cos(x−y)y' = \cos(x-y)y′=cos(x−y) using v=x−yv = x-yv=x−y.
tan(x−y2+π4)=x+C\tan(\frac{x-y}{2} + \frac{\pi}{4}) = x + Ctan(2x−y+4π)=x+C
sin(x−y)=x+C\sin(x-y) = x + Csin(x−y)=x+C
ln∣sec(x−y)+tan(x−y)∣=x+C\ln|\sec(x-y) + \tan(x-y)| = x + Cln∣sec(x−y)+tan(x−y)∣=x+C
tan(x−y)=x+C\tan(x-y) = x + Ctan(x−y)=x+C