MediaWiki renders mathematical equations using a combination of html markup and a variant of LaTeX. Only a limited part of the full TeX language is supported; see below for details. The older PNG images can be set via user preferences.
Additional supported LaTeX extensions are listed below. LaTeX commands. LaTeX packages.
Often mathematical formulae require the addition of many variables Summation or sigma notation is a convenient and simple form of shorthand used to give a concise expression for a sum of the values of a variable. The summation sign This appears as the symbol, Swhich is the Greek upper case letter, S. The summation sign, Sinstructs us to sum the elements of a sequence. A typical element of the sequence which is being summed appears to the right of the summation sign.
You can insert equation symbols outside a math region by using Math AutoCorrect. For more information, see Use Math AutoCorrect rules outside of math regions check box. You can also create math equations using on the keyboard using a combination of keywords and math autocorrect codes.
One of the greatest motivating forces for Donald Knuth when he began developing the original TeX system was to create something that allowed simple construction of mathematical formulae, while looking professional when printed. The fact that he succeeded was most probably why TeX and later on, LaTeX became so popular within the scientific community. Typesetting mathematics is one of LaTeX's greatest strengths.
Note that you do not need to have TeX installed, since matplotlib ships its own TeX expression parser, layout engine and fonts. Any text element can use math text. Regular text and mathtext can be interleaved within the same string. The mathtext font can be selected with the customization variable mathtext.
In LaTeX backslash is used to generate a special symbol or a command. The square root of a number can never be negative by definition. The root of a quadratic equation however, can be either positive or negative.