Plugin: wp-quicklatex (Used by 1,048 domains)

Insert formulas & graphics in the posts and comments using native LaTeX shorthands directly in the text. Inline formulas, displayed equations auto-numbering, labeling and referencing, AMS-LaTeX, TikZ, custom LaTeX preamble. No LaTeX installation required. Easily customizable using UI page. Actively developed and maintained. Visit QuickLaTeX homepage for more info.

• Standard LaTeX expressions can be cut and pasted directly into WordPress posts, pages, and comments; display environments require no enclosures, other expressions require only a surrounding $..$ or \[..\]. No need for enclosing tags [latex] ... [/latex].
• Correct vertical positioning of inline formulas relative to baseline of surrounding text. Say “NO” to jumpy equations produced by other plugins!
• SVG vector graphics support, so that formulas are crisp regardless of scaling in browser.
• (AMS)LaTeX displayed math environments support: equation, align, gather, multiline, flalign, alignat, etc.
• Automatic numbering of displayed equations. Override autonumbering with \tag{} LaTeX command.
• Equation hyper-referencing by standard LaTeX rules with \label{}, \ref{}.
• Custom LaTeX document preamble, allowing added \usepackage{} and \newcommand{}.
• TikZ and pgfplots graphics package support.
• Preview formulas in comments before publishing. Additionally AJAX Comment Preview plugin should be installed to enable this feature.
• Meaningful error messages for mistakes in LaTeX code.
• Precise font properties tuning: size, text and background color.
• Easy style customization using UI or CSS file.
• No LaTeX installation is required.
• QuickLaTeX.com automatically provides formula images, which are then cached on user’s server.
• Administrative settings page for setting global parameters; AJAX-ified.

Just place LaTeX math expressions into your text and enable QuickLaTeX on the page by [latexpage] command.
WP QuickLaTeX will convert them to high-quality images and embed into post. Inline formulas will be properly aligned with the text.
Displayed equations will be auto-numbered by LaTeX rules.
To see plugin in action please visit math-pages on my blog, e.g. Central Differences,
Cubature formulas for the unit disk, Smooth noise robust differentiators, etc.