Vector Fields

A vector field is a vector whose components are functions of two or three variables.
A vector field in the plane is F(x,y)=f1(x,y)i+f2(x,y)j or
(f1(x,y), f2(x,y))
A vector field in three space is F(x,y,z)=f1(x,y,z)i+f2(x,y,z)j+f3(x,y,z)k or (f1(x,y,z), f2(x,y), f3(x,y,z))

At each point, the vector field F is a vector in the plane or space.

Plotting

Streamlines of a Vector Field

Up to Vector Differential Calculus