# Kappa

tenth letter of the Greek alphabet

Kappa (uppercase/lowercase Κ κ) is the letter of the Greek alphabet used to represent the "k" sound in Ancient and Modern Greek. In the system of Greek numerals, it has a value of 20. Letters that came from it include the Roman K and Cyrillic К.

The letter κ always stands for the sound "k" in Greek. It is customary to transliterate (re-write) κ as "c" in English, but this is somewhat problematic since c is pronounced as "s" before e, i and y (which does not happen in Greek).

In mathematics, the lowercase ${\displaystyle \kappa }$ is used to represent the curvature of a curve, while the uppercase Κ is used to represent an ordinal number which is also a cardinal number.[1][2]

## Related pages

• Thermal conductivity, represented by ${\displaystyle \kappa }$

## References

1. "Greek/Hebrew/Latin-based Symbols in Mathematics". Math Vault. 2020-03-20. Retrieved 2020-10-06.
2. "Kappa Symbol in Greek Alphabet". www.greeksymbols.net. Retrieved 2020-10-06.