\underbrace{AB}The \underbrace command in LaTeX is used to place a brace underneath a mathematical expression, often to indicate that the expression is being grouped or to provide additional explanation or annotation below it. This is particularly useful in educational materials or presentations where you want to visually emphasize a part of an equation or expression.
Indicating the number of terms in a summation.
\underbrace{a + b + \cdots + z}_{26 \text{ terms}}Labeling a series with its name.
\underbrace{\frac{1}{n} + \frac{1}{n^2} + \cdots}_{\text{Harmonic series}}Explaining the meaning of an integral.
\underbrace{\int_0^1 x^2 \, dx}_{\text{Area under the curve}}