Start with vector when possible
SVG gives design applications real vector paths that remain sharp as the equation scales. It is the best starting point for layout software that supports SVG well.
Use Print PNG when needed
If your destination requires a raster image, choose Print PNG. Its 300 dpi means it contains more pixels per inch, so it is sharper on paper at the intended physical size. Use Standard PNG instead when the destination does not respect density metadata.
Review it in context
Place the equation in the final layout and inspect it at its intended size. Every app has its own import behaviour, so the destination remains the final check.