How to make formule bigger in org-mode of Emacs?

emacs, latex, org-mode

Solution

According to the documentation

or `(info "(org) Previewing LaTeX fragments")`

You can customize the variable `org-format-latex-options' to
influence some aspects of the preview. In particular, the `:scale'
(and for HTML export, `:html-scale') property can be used to
adjust the size of the preview images.

A quick C-hv`org-format-latex-options`RET gives us:

org-format-latex-options is a variable defined in `org.el'.
Its value is (:foreground default :background default :scale 1.0 :html-foreground "Black" :html-background "Transparent" :html-scale 1.0 :matchers
             ("begin" "$1" "$" "$$" "\\(" "\\["))


Documentation:
Options for creating images from LaTeX fragments.
[snip]
:scale       a scaling factor for the size of the images, to get more pixels
[snip]

For example, to set the scale to `2.0`:

(setq org-format-latex-options (plist-put org-format-latex-options :scale 2.0))

Problem

I found Org-mode + LaTeX to be a very wonderful tool. How can I alter the scale of formula? Currently it is too small for me. I know how to scale the Emacs font (C-x+), but this does not work for LaTeX formulas. How can make the LaTeX formulae bigger in Org-mode? I have tired to change some parameters, but the problem still remains. Thank you for your patience!

Original source