∫CF⋅t ds=∫CF⋅dr=∫C(F1dx+F2dy+F3dz)=∫t0tfF(r(t))⋅r′(t) dt t represents the unit tangent vector of the path If F represents a vector field for some force, then the vector line integral represents the work done by the force dx=x′(t)dt, dy=y′(t)dt, dz=z′(t)dt, where r′(t)=⟨x′(t),y′(t),z′(t)⟩ ∫C∇f⋅dr=f(Sf)−f(S0) Fundamental Theorem of Vector Integrals