Calculus & Analysis Symbols

Calculus & Analysis

Used in the study of change, limits, and summation.

Symbol	Name	Meaning / Usage
$\infty$	Infinity	A quantity larger than any real number.
$\sum$	Summation (Sigma)	Sum of a sequence of numbers ( $\sum_{i=1}^{n} a_i$ ).
$\int$	Integral	Represents the area under a curve ( $\int f(x) \, dx$ ).
$\iint$	Double Integral	Integration over a 2D area ( $\iint_D f(x,y) \, dx \, dy$ ).
$\frac{d}{dx}$ or $f'(x)$	Derivative	Instantaneous rate of change of $f$ with respect to $x$ ( $\frac{d}{dx} f(x)$ ).
$\frac{\partial}{\partial x}$	Partial Derivative	Derivative of a multi-variable function (e.g., $\frac{\partial f}{\partial x}$ ).
$\lim$	Limit	Value a function approaches as the input approaches some value ( $\lim_{x \to \infty} f(x)$ ).
$\Delta$	Delta	Represents a change or difference ( $\Delta x = x_2 - x_1$ ).
$\nabla$	Nabla / Del	Vector differential operator (gradient) ( $\nabla f$ ).
$f(x)$	Function of x	Maps an input $x$ to an output ( $f(x) = x^2$ ).