Evaluated At in LaTeX (\Big|_{a}^{b})

Where it is used

Vertical evaluation bar with limits, showing an antiderivative evaluated from a to b.

After integrating, writing F(x)\Big|_{a}^{b} = F(b) - F(a) is the standard shorthand from the fundamental theorem of calculus. \Big fixes the bar at one enlarged size, which suits ordinary fractions; for taller expressions use \bigg| or pair \left. with \right|_{a}^{b} so the bar grows to match whatever precedes it. Some authors prefer square brackets, \Big[ F(x) \Big]_a^b, which leave no doubt about how much is being evaluated. A plain | without sizing is too short and makes the limits crowd the antiderivative, especially after a fraction.

Minimal compilable example

Paste this into an empty .tex file and compile it with pdfLaTeX, XeLaTeX or LuaLaTeX.

\documentclass{article}
\begin{document}
Evaluated At: $\Big|_{a}^{b}$

\[ \int_0^2 x\,dx = \frac{x^2}{2}\Big|_{0}^{2} = 2 \]
\end{document}

Related symbols

• Approaches\to
• Double Dot\ddot{x}
• Dot\dot{x}
• Double Primef''(x)
• Prime Derivativef'(x)
• Differentialdx

Frequently asked questions

How do I write Evaluated At in LaTeX?

Type \Big|_{a}^{b} in math mode, for example $\int_0^2 x\,dx = \frac{x^2}{2}\Big|_{0}^{2} = 2$. It works in plain LaTeX without loading any package.

Which package do I need for \Big|_{a}^{b}?

None. \Big|_{a}^{b} is part of standard LaTeX, so it compiles with nothing in the preamble but the document class.

Can I use \Big|_{a}^{b} in text mode, or only in math mode?

Only in math mode. Outside $...$ LaTeX stops with "Missing $ inserted", so write $\Big|_{a}^{b}$ in running text.