[Tex/LaTex] Square root in fraction space problem

fractionsmath-mode

I'm having some troubles with the square root symbol within a fraction.
This code

\documentclass{book}

\begin{document}
\begin{equation}
h_4 = \frac{\sqrt{1.5 \gamma_4 -3.5}-1}{18}
 \end{equation}
\begin{equation}
h_3 = \frac{\gamma_3}{4+ \sqrt{6\gamma_4-14}}
\end{equation}
\end{document}

returns this

$square root within a fraction$

Now, is it just me, or the horizontal line of the square root is really close both to the numbers below it and to the fraction line above it?

I find this a little clumsy.

Is there a solution? Or this is just my paranoia? 😛

Thank you very much

Best Answer

If it is not too large, \strut may be a solution (an original one left for comparision). According Mico's sugestion, \mathstrut gives a value between them. You can also adjust vertical spacing exactly to expected values, using e.g. \rule.

\documentclass{book}
\newcommand\uprule{\rule{0mm}{1.9ex}} %shortcut macro
\begin{document}
\begin{equation}
h_4 = \frac{\sqrt{1.5 \gamma_4 -3.5}-1}{18}
 \end{equation}
\begin{equation}
h_3 = \frac{\gamma_3}{4+ \sqrt{6\gamma_4-14}}
\end{equation}

strut

\begin{equation}
h_4 = \frac{\sqrt{\strut1.5 \gamma_4 -3.5}-1}{18}
 \end{equation}
\begin{equation}
h_3 = \frac{\gamma_3}{4+ \sqrt{\strut6\gamma_4-14}}
\end{equation}

mathstrut

\begin{equation}
h_4 = \frac{\sqrt{\mathstrut1.5 \gamma_4 -3.5}-1}{18}
 \end{equation}
\begin{equation}
h_3 = \frac{\gamma_3}{4+ \sqrt{\mathstrut6\gamma_4-14}}
\end{equation}

rule

\begin{equation}
h_4 = \frac{\sqrt{\uprule1.5 \gamma_4 -3.5}-1}{18}
 \end{equation}
\begin{equation}
h_3 = \frac{\gamma_3}{4+ \sqrt{\uprule 6\gamma_4-14}}
\end{equation}
\end{document}

enter image description here

Related Solutions

[Tex/LaTex] How continue an equation next line

I suggest using the multlined environment from mathtools to break the radicand . You also can choose not to break it, but to type in medsize (~80 % of \displaystyle) with the \mediummath command from nccmath. I took the opportunity to clean your code:

\documentclass[11pt,a4paper,twocolumn]{article}
\usepackage[utf8]{inputenc}
\usepackage{mathtools, nccmath}

\begin{document}

\begin{equation*}
    \bigl| \dot{r} \bigr| =
    \sqrt{\begin{multlined}[b] -\!\bigl(e^{-t} ( \cos t + \sin t )\bigr)^2 + \\ \bigl(e^{-t} (\cos t + \sin t)\bigr)^2 + \bigl(-e^{-t}\bigr)^2 \end{multlined}}
\end{equation*}
\begin{align*}
    \bigl| \dot{r} \bigr| & =
    \sqrt{\medmath{ -\!\bigl(e^{-t} ( \cos t + \sin t )\bigr)^2 + \bigl(e^{-t} (\cos t + \sin t)\bigr)^2 + \bigl(-e^{-t}\bigr)^2}} \\
         & = \sqrt{ -\!\bigl(e^{-t} ( \cos t + \sin t )\bigr)^2 + \bigl(e^{-t} (\cos t + \sin t)\bigr)^2 + \bigl(-e^{-t}\bigr)^2}
\end{align*}

\end{document}

[Tex/LaTex] How to adjust/increase the height of square root

Getting square roots right requires a bit of manual intervention.

I essentially add a phantom \beta^K so TeX will see some more height, but not too much to make it choose the next size of the radical.

Also I add a phantom \Big| to the denominator, but smashed at the bottom so the apparent height will be increased, thus moving down the radical from the fraction line.

Important suggestion: {^s_i\lambda} and similar is not the best way to deal with prescripts; with \mathtools there is \prescript which will adapt the height of the prescripts to the object they apply to and also adds a thin space in order to make clear that the prescripts aren't scripts to the symbol at the left.

Finally, dcases* avoids the need for \dfrac and for \text.

\documentclass{article}
\usepackage{amsmath,mathtools,amssymb}
\usepackage{bm}

\begin{document}

The original equation is
\begin{equation}
    \delta {^s_i\lambda} = 
    \begin{cases}
            \pm \dfrac{{^s\overline{\Delta T}}}{\sqrt[]{\delta {^s_1\bm{u}_l} \cdot \delta {^s_1\bm{u}_l} + \beta}}                                        & \! \text{if} \; i = 1           \\[1em]
            - \dfrac{\delta{^s_1\bm{u} \cdot \delta{^s_1\bm{u}_r}}}{\delta {^s_1\bm{u}} \cdot \delta {^s_i\bm{u}_l} + \beta \delta {^s_1\lambda}}   & \! \text{otherwise}
    \end{cases}
\end{equation}
and now the modified one
\begin{equation}
\delta\prescript{s}{i}{\lambda} = 
\begin{dcases*}
  \pm \frac{
    \prescript{s}{}{\overline{\Delta T}}
  }{
    \smash[b]{\vphantom{\Big|}}
    \sqrt{
      \vphantom{\beta^K}
      \delta\prescript{s}{1}{\bm{u}_l} \cdot
      \delta\prescript{s}{1}{\bm{u}_l} + \beta
    }
  } & if $i = 1$
\\[1ex]
  -\frac{
     \delta\prescript{s}{1}{\bm{u}} \cdot \delta\prescript{s}{1}{\bm{u}_r}
   }{
     \delta\prescript{s}{1}{\bm{u}} \cdot \delta\prescript{s}{i}{\bm{u}_l} +
     \beta \delta\prescript{s}{1}{\lambda}
   } & otherwise
\end{dcases*}
\end{equation}

\end{document}

Best Answer

Related Solutions

[Tex/LaTex] How continue an equation next line

[Tex/LaTex] How to adjust/increase the height of square root

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