Delta (Δ, δ)
Quick Info
- Pronunciation: DEL-tuh
- English: d
- Common Use: Change in value (Δx)
Historical Background
Fourth letter of the Greek alphabet, derived from Phoenician letter "daleth". The name comes from the Phoenician word for door, and its triangular shape evolved from the early pictograph representing a door or entrance.
Scientific Applications
Mathematics
Change in value
Physics
Uncertainty
Thermodynamics
Heat change
Chemistry
Partial charge
Symbol Codes
Unicode
Uppercase
- Code: U+0394
- Hex: Δ
- Decimal: Δ
Lowercase
- Code: U+03B4
- Hex: δ
- Decimal: δ
HTML
Uppercase
Δ
HTML entity for uppercase Delta
Lowercase
δ
HTML entity for lowercase delta
LaTeX
Uppercase
\Delta
LaTeX command for uppercase Delta
Lowercase
\delta
LaTeX command for lowercase delta
Common Usage
Mathematics
Calculus
Change or difference in values
Linear Algebra
Determinants and discriminants
Analysis
Small variations and increments
Physics
Quantum Mechanics
Uncertainty relations
Thermodynamics
Changes in state variables
Mechanics
Displacement and work
Chemistry
Bonding
Partial charge distribution
Reactions
Heat of reaction (ΔH)
Solutions
Concentration changes
Common Applications
Calculus
Change in function value
Derivative limit
Volume change
Physics
Distance traveled
Mass-energy equivalence
Momentum change
Special Applications
Thermodynamics
Entropy change
Gibbs free energy
Internal energy change
Quantum Mechanics
Heisenberg uncertainty
Energy quantum
Kronecker delta
Field Applications
Mathematics
- • Difference equations
- • Finite differences
- • Discriminant functions
- • Change calculations
Chemistry
- • Electronegativity
- • Reaction energetics
- • Bond polarization
- • State changes
Engineering
- • Error analysis
- • System changes
- • Control theory
- • Signal processing
Writing Guidelines
Uppercase is a triangular shape (Δ), lowercase has a curved hook (δ). In handwriting, ensure the uppercase Delta maintains its triangular form and the lowercase delta has a clear loop with a distinctive tail. Be careful to distinguish δ from the Latin d and the partial derivative symbol ∂.
How to Type Delta
Windows
Alt Code
- Hold Alt
- Type 235 for δ
- Release Alt
Character Map
- Open Character Map
- Select Greek
- Find and copy Delta
Unicode
- Hold Alt + X
- Type 03B4
- Release Alt + X
macOS
Option Key
- Press Option + j for δ
Character Viewer
- Press Control + Command + Space
- Select Greek
- Click Delta
Linux
Compose Key
- Press Compose + d + d for δ
Unicode
- Press Ctrl + Shift + U
- Type 03B4
- Press Enter
Frequently Asked Questions
What is the difference between Delta (Δ) and Latin D?
While they represent similar sounds, Delta and Latin D have different shapes and uses. Delta is triangular (Δ) and is commonly used to represent change or difference in mathematics and science.
What's the difference between Δ and δ in mathematics?
Uppercase Delta (Δ) typically represents a large or finite change, while lowercase delta (δ) often represents a small or infinitesimal change. For example, Δx means the total change in x, while δx means a tiny increment.
How is delta used in chemistry?
In chemistry, delta (δ) is used to indicate partial charges in molecules (δ+ for partially positive, δ- for partially negative), while uppercase Delta (Δ) represents changes in variables like temperature (ΔT) or enthalpy (ΔH).
What's the difference between δ and ∂?
While they look similar, δ (delta) represents small changes or variations, while ∂ (partial derivative) is specifically used for partial differentiation in calculus. They serve different mathematical purposes and should not be confused.