# LaTeX Scale Adjacent Terms' Grouping Symbols Together

I have two adjacent terms in a LaTeX equation, and I'd like the brackets around both to scale to the height of both terms.

For example \left[ a \right] \left[ \frac{b}{c} \right] generates:

I'd like all four brackets to both be the same height.

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\biggl[a\biggr]\biggl[\dfrac{b}{c}\biggr] –  Gonzalo Medina Jul 29 '13 at 22:08
Take a look at the scalerel package, I had a similar question and got this excellent answer: tex.stackexchange.com/a/125722/19326. (It was about Images), but if you look inside the scalerel documentation you will find it talking about symbol scaling too, right in teh beginning of chapter 2 and chapter 3. \stretchrel might be what you need. This is overkill if it is just for one occurence though. –  ted Jul 29 '13 at 22:26
@GonzaloMedina, not as elegant as Werner's. –  Ian Mallett Jul 30 '13 at 0:55
@ted, unfortunately, this formula is going in MathJax, which doesn't seem to support \usepackage{...}. I ran into that problem earlier when trying to scale a summation. –  Ian Mallett Jul 30 '13 at 0:55
@IanMallett "elegance" lies in the eye of the beholder :-) Anyway I wouldn't recommend using \left, \right, except perhaps in very, very few cases. –  Gonzalo Medina Jul 30 '13 at 1:21
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## 1 Answer

In general, you could use

\left[\vphantom{\frac{b}{c}}a\right] \left[\frac{b}{c}\right]


using \vphantom to obtain the appropriate height of something without introducing an unnecessary width insertion. Alternatively, use fixed-sized scaled delimiters using "big"-variants. From the amsmath user guide (section 4.14.1 Delimiter sizes, p 15):

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Excellent. Thank you. –  Ian Mallett Jul 30 '13 at 0:55
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