Fixing the spacing of overbrace and underbrace contents relative to large brackets

Question

Consider the code for the MnWE:

\documentclass{article}
\usepackage{physics}
\usepackage{mathtools}
\usepackage{amsmath}


\begin{document}

    \begin{equation}
        \norm{f - L}_{\infty} = \overbrace{\abs{\frac{K_2}{2}}}^{\mathclap{\text{worst $f''(x)$ over all subintervals}}}\left(\underbrace{\frac{h}{2}}_{\mathclap{\text{worst (b - a)}}}\right)^2
    \end{equation}

\end{document}

Which results in the following output:

What is the right way to fix the text clash?

Answer 1

Simply move all the left/right bracketing and exponentiation, into the underbrace argument:

\documentclass{article}
\usepackage{physics}
\usepackage{mathtools}
\usepackage{amsmath}


\begin{document}

    \begin{equation*}
        \norm{f - L}_{\infty} = \overbrace{\abs{\frac{K_2}{2}}}^{\mathclap{\text{worst $f''(x)$ over interval}}}\underbrace{\left(\frac{h}{2}\right)^2}_{\mathclap{\text{worst (b - a)}}}
    \end{equation*}

\end{document}

This also fixes the otherwise odd sizing of the left/right brackets.