Math mode ($ vs. $$)
Putting text between dollar signs will activate "math mode" where you can format equations and code in TeX. A single pair of dollar signs (e.g. $y = mx + b$) produces in-line math mode (ie able to use symbol for $\lambda$)
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Use those curly brackets! { } are your friend!
fractions= ${#\over #}$, and \overline {} will work for larger equations.
subscript: _
superscript: ^
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