I am trying to write this equation enter image description here

So far, I have this:

\resizebox{0.85\hsize}{!}{\frac{{\Bigg(\prod_{j=1}^n f_j\Bigg) 
    \Bigg(\sum_{i=1}^{nME}P_{ME(i)}.C_{FME(i)}.SFC_{ME(i)}\Bigg) + 
    \Bigg(\Bigg(\prod_{j=1}^n f_j.\sum_{i=1}^{nPTI} P_{PTI(i)}-
    C_{FAE}.SFC_{AE}\Bigg) -

But I can't get the denominator where I want it to be :

enter image description here

How can I fix this? Thanks :)

  • You are not opening math mode in the box to resize and get several errors.
    – egreg
    Aug 3, 2019 at 10:59
  • 1
    Off topic: complicated equations are very easy to write with LyX: lyx.org
    – AndréC
    Aug 3, 2019 at 11:08

2 Answers 2


You shouldn't force your readers to look for a magnifying glass; it's better to split the thing across lines.



&\frac{1}{f_i\cdot f_c\cdot f_l\cdot \vr{Capacity}\cdot f_w\cdot V_{\vr{ref}}} \\
& \cdot\biggl[
   \biggl(\,\prod_{j=1}^n f_j\biggr)
   \biggl(\,\sum_{i=1}^{n_{\vr{ME}}} P_{\vr{ME}(i)}\cdot
     C_{\vr{FME}(i)}\cdot \vr{SFC}_{\vr{ME}(i)}\biggr)\\
&\qquad +
   (P_{\vr{AE}}\cdot C_{\vr{FAE}}\cdot \vr{SFC}_{\vr{AE}}) \\
&\qquad +
   \biggl(\biggl(\,\prod_{j=1}^n f_j\cdot \sum_{i=1}^{n_{\vr{PTI}}} P_{\vr{PTI}(i)}-
     \sum_{i=1}^{n_{\vr{eff}}} f_{\vr{eff}(i)}\cdot P_{\vr{AEeff}(i)}\biggr)
     C_{\vr{FAE}}\cdot \vr{SFC}_{\vr{AE}}\biggr) \\
&\qquad -
    \biggl(\,\sum_{i=1}^{n_{\vr{eff}}} f_{\vr{eff}(i)}\cdot P_{\vr{eff}(i)}\cdot
    C_{\vr{FME}}\cdot \vr{SFC}_{\vr{ME}}\biggr)


The formatting of superscripts should be studied in greater detail. Never use a period to denote multiplication.

enter image description here

  • Haha, that's true. Thank you so much
    – Nikhil
    Aug 3, 2019 at 13:38

Rather than try to reduce the size of the equation in order to make it fit on a single line, I would employ a multline environment and typeset the equation across four lines: Three lines for the numerator, and the fourth and final line for the denominator. Note that in the following solution, I've dispensed with \frac notation.

enter image description here

\usepackage{amsmath} % for 'multline' env.
\Biggl\{\biggl(\,\prod_{j=1}^n f_j\biggr) 
+ P_{\mathrm{AE}}\cdot C_{\mathrm{FAE}}
\cdot \mathit{SFC}_{\!\mathrm{AE}}\\
+ \biggl[\biggl(\,\prod_{j=1}^n f_j\cdot 
\sum_{i=1}^{n_{\mathrm{PTI}}} P_{\mathrm{PTI}(i)}
C_{\mathrm{FAE}}\cdot \mathit{SFC}_{\!\mathrm{AE}}\biggr] \\
\cdot P_{\mathrm{eff}(i)}\cdot C_{\mathrm{FME}}
\cdot \mathit{SFC}_{\mathrm{ME}}\biggr) \Biggr\}\\
\Big/\Bigl\{f_i\cdot f_c\cdot f_l\cdot \mathit{Capacity}
\cdot f_w\cdot V_{\mathrm{ref}}\Bigr\}

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