∂

Look up ∂ in Wiktionary, the free dictionary.

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 Jacobian, .
• The boundary of a set in topology.
• The boundary operator on a chain complex in homological algebra.
• The boundary operator of a differential graded algebra.
• The Dolbeault operator on complex differential forms.

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.

References