[tex]\displaystyle \int (\sin 2x + \cos 2x)~ dx\\\\=\displaystyle \int \sin 2x ~dx + \displaystyle \int \cos 2x ~ dx\\\\=-\dfrac{\cos 2x}2 + \dfrac{\sin 2x}2 +C\\\\=\dfrac{\sin 2x - \cos 2x}2+C[/tex]
