Vector Calculus Formula Reference
Vector Calculus Formulas
Introductory to IntermediateOverview
Vector calculus is the field that handles differential operators and integral theorems for scalar and vector fields. It provides the indispensable mathematical machinery for describing physical laws such as Maxwell's equations in electromagnetism and the Navier-Stokes equations in fluid dynamics.
Looking for matrix calculus? For derivatives of functions whose variables are vectors or matrices (gradient vectors, Jacobian matrices, Hessian matrices, etc.), see Matrix Calculus.
Quick-Reference Table of Vector Differential Operators
The four fundamental operations of vector calculus are summarized below. All can be expressed uniformly in terms of the nabla operator $\nabla = (\partial/\partial x,\, \partial/\partial y,\, \partial/\partial z)$.
| Operation | Notation | Input → Output | Definition | Physical meaning |
|---|---|---|---|---|
| Gradient (grad) | $\nabla f$ | Scalar field → Vector field | $\left(\dfrac{\partial f}{\partial x},\, \dfrac{\partial f}{\partial y},\, \dfrac{\partial f}{\partial z}\right)$ | Direction of steepest ascent and rate of change |
| Divergence (div) | $\nabla \cdot \mathbf{A}$ | Vector field → Scalar field | $\dfrac{\partial A_x}{\partial x} + \dfrac{\partial A_y}{\partial y} + \dfrac{\partial A_z}{\partial z}$ | Strength of the source/sink |
| Curl | $\nabla \times \mathbf{A}$ | Vector field → Vector field | Determinant form (details) | Strength and axis of rotation |
| Laplacian | $\nabla^2 f$ | Scalar field → Scalar field | $\dfrac{\partial^2 f}{\partial x^2} + \dfrac{\partial^2 f}{\partial y^2} + \dfrac{\partial^2 f}{\partial z^2}$ | Difference from the surrounding average |
Important identities
- $\nabla \times (\nabla f) = \mathbf{0}$ — A gradient field is always irrotational
- $\nabla \cdot (\nabla \times \mathbf{A}) = 0$ — A curl field is always solenoidal (source-free)
Contents
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Chapter 1
Gradient, Divergence, Curl, and Laplacian
Definitions, properties, and physical meaning of the nabla operator $\nabla$ and the four fundamental operations
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Chapter 2
Vector Calculus Identities
Algebraic identities for dot and cross products, product rules involving $\nabla$, and second-order derivative identities
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Chapter 3
Coordinate-System Formulas
Expressions for grad, div, curl, and the Laplacian in Cartesian, cylindrical, and spherical coordinates
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Chapter 4
Integral Theorems
Divergence theorem (Gauss), Stokes' theorem, and Green's theorem
Prerequisites
- Partial derivatives of multivariable functions
- Dot product and cross product of vectors
- Basics of multiple integrals, line integrals, and surface integrals