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The character (html element: ∂ or ∂, unicode: U+2202) or is a stylized d mainly used as a mathematical symbol to denote a partial derivative such as (read as "the partial derivative of z with respect to x"). The symbol was originally introduced by Legendre in 1786, but only gained popularity when it was used by Jacobi in 1841.[1]

is also used to denote the following:

The symbol may be referred to as "del",[2] "dee",[3] "partial dee",[4] "partial", "curly dee",[5] or "dabba".[6]

The lowercase Cyrillic De can look similar.


  1. ^ Aldrich, John. "Earliest Uses of Symbols of Calculus". Retrieved 16 January 2014. 
  2. ^ Bhardwaj, R.S. (2005), Mathematics for Economics & Business (2nd ed.), p. 6.4 
  3. ^ Silverman, Richard A. (1989), Essential Calculus: With Applications, p. 216 
  4. ^ Pemberton, Malcolm; Rau, Nicholas (2011), Mathematics for Economists: An Introductory Textbook, p. 271 
  5. ^ Bowman, Elizabeth (2014), Video Lecture for University of Alabama in Huntsville 
  6. ^ Gokhale, Mujumdar, Kulkarni, Singh, Atal, Engineering Mathematics I, p. 10.2, Nirali Prakashan ISBN 8190693549.