Greek letters

2. (Ο, ο) – The fifteenth letter, historically used in Greek numbering.
5. (Ζ, ζ) – Used in physics (zeta potential) and the Riemann zeta function in math.
7. (Θ, θ) – Commonly used for angles in trigonometry and temperature in thermodynamics.
8. (Κ, κ) – Used in statistics (kappa coefficient) and physics (wave numbers).
9. (Μ, μ) – Symbolizes the coefficient of friction, micro- (μ) as a unit prefix, and mean in statistics.
11. (Α, α) – The first letter of the Greek alphabet; often represents the beginning or first in a series.
13. (Ξ, ξ) – Used in statistics and physics for random variables and wave functions.
14. (Λ, λ) – Represents wavelength in physics and eigenvalues in linear algebra.
15. (Ν, ν) – Represents frequency in physics and fluid dynamics (kinematic viscosity).

1. (Ι, ι) – Means a very small amount, used metaphorically in English.
3. (Δ, δ) – The fourth letter; symbolizes change in mathematics (Δ) and partial derivatives (∂).
4. (Β, β) – The second letter; used in finance (beta coefficient) and physics (beta particles).
6. (Γ, γ) – The third letter; represents the gamma function in math and gamma rays in physics.
10. (Ε, ε) – Represents small quantities in calculus and limits in mathematics.
12. (Η, η) – Represents efficiency in physics and elasticity in economics.