How do I include a formula like f=ma inline with text in LaTeX?

[chimay]

I have problems to write the formulas correctly . How can I include them in only one line instead of obtain this effect(i.e):
-I want to to include the formula $$f=ma$$ in this line!

 

[micromass]

Use

[itex]f=ma[/itex]

instead of tex.

Also see our LaTeX-guide: https://www.physicsforums.com/showthread.php?t=546968

 

[chimay]

Thanks!