Greek alphabet  



History  
Use in other languages  
Related topics  
Tau (/ˈtɔː, ˈtɒ, ˈtaʊ/;^{[1]} uppercase Τ, lowercase τ or ; Greek: ταυ [taf]) is the nineteenth letter of the Greek alphabet, representing the voiceless dental or alveolar plosive IPA: [t]. In the system of Greek numerals, it has a value of 300.
The name in English is pronounced /taʊ/ or /tɔː/,^{[2]} but in Greek it is [taf].^{[3]}^{[4]} This is because the pronunciation of the combination of Greek letters αυ can have the pronunciation of either [ai], [av] or [af], depending on what follows and if a diaeresis is present on the second vowel (see Greek orthography).
Tau was derived from the Phoenician letter taw (𐤕).^{[5]} Letters that arose from tau include Roman T and Cyrillic Te (Т, т).
The letter occupies the Unicode slots U+03C4 (lowercase) and U+03A4 (uppercase). In HTML, they can be produced with named entities (τ
and Τ
), decimal references (τ
and Τ
), or hexadecimal references (τ
and Τ
).
See also: Greek letters used in mathematics, science, and engineering § Ττ (tau) 
The lowercase letter τ is used as a symbol for:
For the Greek and Coptic letter tau:^{[17]}
Preview  Τ  τ  Ⲧ  ⲧ  

Unicode name  GREEK CAPITAL LETTER TAU  GREEK SMALL LETTER TAU  COPTIC CAPITAL LETTER TAU  COPTIC SMALL LETTER TAU  
Encodings  decimal  hex  dec  hex  dec  hex  dec  hex 
Unicode  932  U+03A4  964  U+03C4  11430  U+2CA6  11431  U+2CA7 
UTF8  206 164  CE A4  207 132  CF 84  226 178 166  E2 B2 A6  226 178 167  E2 B2 A7 
Numeric character reference  Τ 
Τ 
τ 
τ 
Ⲧ 
Ⲧ 
ⲧ 
ⲧ 
Named character reference  Τ  τ  
DOS Greek  147  93  171  AB  
DOS Greek2  208  D0  238  EE  
Windows 1253  212  D4  244  F4  
TeX  \tau 
For the mathematical letter tau:^{[18]}^{[19]}^{[20]}^{[21]}^{[22]}^{[23]}^{[24]}^{[25]}^{[26]}^{[27]}
Preview  𝚻  𝛕  𝛵  𝜏  𝜯  𝝉  

Unicode name  MATHEMATICAL BOLD CAPITAL TAU 
MATHEMATICAL BOLD SMALL TAU 
MATHEMATICAL ITALIC CAPITAL TAU 
MATHEMATICAL ITALIC SMALL TAU 
MATHEMATICAL BOLD ITALIC CAPITAL TAU 
MATHEMATICAL BOLD ITALIC SMALL TAU  
Encodings  decimal  hex  dec  hex  dec  hex  dec  hex  dec  hex  dec  hex 
Unicode  120507  U+1D6BB  120533  U+1D6D5  120565  U+1D6F5  120591  U+1D70F  120623  U+1D72F  120649  U+1D749 
UTF8  240 157 154 187  F0 9D 9A BB  240 157 155 149  F0 9D 9B 95  240 157 155 181  F0 9D 9B B5  240 157 156 143  F0 9D 9C 8F  240 157 156 175  F0 9D 9C AF  240 157 157 137  F0 9D 9D 89 
UTF16  55349 57019  D835 DEBB  55349 57045  D835 DED5  55349 57077  D835 DEF5  55349 57103  D835 DF0F  55349 57135  D835 DF2F  55349 57161  D835 DF49 
Numeric character reference  𝚻 
𝚻 
𝛕 
𝛕 
𝛵 
𝛵 
𝜏 
𝜏 
𝜯 
𝜯 
𝝉 
𝝉 
Preview  𝝩  𝞃  𝞣  𝞽  

Unicode name  MATHEMATICAL SANSSERIF BOLD CAPITAL TAU 
MATHEMATICAL SANSSERIF BOLD SMALL TAU 
MATHEMATICAL SANSSERIF BOLD ITALIC CAPITAL TAU 
MATHEMATICAL SANSSERIF BOLD ITALIC SMALL TAU  
Encodings  decimal  hex  dec  hex  dec  hex  dec  hex 
Unicode  120681  U+1D769  120707  U+1D783  120739  U+1D7A3  120765  U+1D7BD 
UTF8  240 157 157 169  F0 9D 9D A9  240 157 158 131  F0 9D 9E 83  240 157 158 163  F0 9D 9E A3  240 157 158 189  F0 9D 9E BD 
UTF16  55349 57193  D835 DF69  55349 57219  D835 DF83  55349 57251  D835 DFA3  55349 57277  D835 DFBD 
Numeric character reference  𝝩 
𝝩 
𝞃 
𝞃 
𝞣 
𝞣 
𝞽 
𝞽 
These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style.