Partial Differential ∂

The Partial Differential character (∂) is a standard HTML entity defined in the HTML specification. In HTML source code, it can be written using the named entity reference ∂, the decimal numeric character reference ∂, or the hexadecimal numeric reference ∂. The character is assigned Unicode code point U+2202 in the Universal Character Set.

The partial differential symbol is a stylized lowercase 'd' used in multivariable calculus to denote partial derivatives. It indicates differentiation with respect to one variable while holding others constant. The symbol is essential in physics (thermodynamics, fluid dynamics), engineering, and advanced mathematics.

Mathematical HTML entities enable web authors to display proper mathematical notation without relying on images or specialized rendering libraries like MathJax or KaTeX. While complex equations and multi-line formulas may still benefit from dedicated math typesetting tools, individual symbols expressed as HTML entities render quickly, remain accessible to screen readers, and can be styled with CSS just like regular text content.

When deciding how to encode the Partial Differential character in your HTML documents, the named entity ∂ is generally the most readable choice for developers reviewing or maintaining source code. The decimal form ∂ and hexadecimal form ∂ are equally valid alternatives that work in contexts where named entities may not be supported, or when generating HTML output programmatically from server-side code. All three representations produce identical visual output in every modern web browser.

Use the partial differential symbol in calculus expressions involving functions of multiple variables, partial differential equations, and physics notation. It distinguishes partial derivatives from ordinary derivatives and is fundamental to fields like thermodynamics, electromagnetic theory, and differential geometry.