∫cF⋅ⅆ⁡s=∫abF⁢(c⁡(t))⋅c′⁡(t)⁢ⅆ⁡t=∫ab(F1⁢ⅆ⁡xⅆ⁡t+F2⁢ⅆ⁡yⅆ⁡t+F3⁢ⅆ⁡zⅆ⁡t)⁢ⅆ⁡t=∫cF1⁢ⅆ⁡x+F2⁢ⅆ⁡y+F3⁢ⅆ⁡z.