It's not a font issue. Unicode characters like below are available in most all fonts.
But a lot of equations require more than special characters, so a lot of what you see on the internet are graphics. Try to move the equation with your mouse, and it if moves as a unit, it is a graphic.
some of the thousands of unicode characters:
Note, if you don't see math and greek symbols below, then your PC will not read unicode characters, and it needs either an upgrade or it has a configuration problem.
± × ÷
º ± ¹ ² ³ ³
£ ¢ ¥ € ½ ½ ¼ ¾ Å ( Å