What 𝞉 means
It measures change in one input while holding the others fixed. In 𝞉f/𝞉x, x is the input being varied.
French mathematician Condorcet used the “curly d,” , for partial differences in 1770. In 1786, Legendre used it to mark partial derivatives against total change across inputs, then dropped it. Jacobi reused the sign in 1841. In 1902, mathematicians still debated how clearly formulas should show which variables stayed fixed.
Don't confuse it with
2
Related characters
3
Combination ideas
3Partial derivative of f with respect to x.
Second time derivative of u, as in the wave equation.
Boundary of the region Ω.
Questions people ask
1Why does 𝞉 show as a box?
Your browser or document font may lack it. As of 2026, without a suitable math font, the glyph may be absent or look different.
More like this
13
How to type or find 𝞉
- Search it as
- partial derivative · curly d · partial sign
- Shows up in
- Anything that takes text · its shape is whatever your font draws
Windows (Word)
Windows
macOS
HTML
𝞉CSS
\1D789How do I type 1D789 in Word?
In Word for Windows, type 1D789 without U, then press AltX.
Codes and encoding1 code points
HTML decimal
𝞉
HTML hex
𝞉
CSS content
content: "\1D789";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%F0%9D%9E%89
1
On screen
1
Code points
2
JS .length
4
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.