p:partial (偏微) del=(p/px)Xdirection+(p/py)Ydirection+(p/pz)Zdirection gradient V=(pV/px)Xdirection+(pV/py)Ydirection+(pV/pz)Zdirection vector divergence V=pV/px)+(pV/py)+(pV/pz ) scalar curl V=determinant Xdirection,Ydirection,Zdirection p/px, p/py, p/pz Ax, Ay , Az 方向導數=gradient v *單位向量