Btukfyl

So what I am trying to type is the square of the derivative of vector x. I tried dot{vec{x}}^{,2} as well as dot{vec{x}^2}, but the outputs came out to be very offset. Is there a correct way to do this?

The code I used is:

begin{equation}    

L=frac{1}{2} m dot{vec{x^2}}     

end{equation}

which give me

I'd probably do

documentclass{article}

usepackage{amsmath}

begin{document}

begin{equation}    

L=frac{1}{2} m Dot{vec{x}}^2     

end{equation}

end{document}

because the Lagrange function is a function of the square of the time derivative of x (and not the time derivative of the square of x).

The first or third option below may be close to what you're looking for. Or, switch from Newton-style to Leibniz-style notation for the derivative, as shown by the fourth option (newly fixed to incorporated @marmot's comment). A separate comment: to make the frac{1}{2} term less visually dominant, consider using tfrac instead of frac.

documentclass{article}

usepackage{amsmath} % for tfrac macro and general accent-placement support

begin{document}

[

tfrac{1}{2}m dot{vec{x}} ^2     quad

tfrac{1}{2}m{dot{vec{x}}}^2     quad

tfrac{1}{2}m{dot{vec{x}}}^{,2} quad

tfrac{1}{2}mbigl(tfrac{mathrm{d}vec{x}}{mathrm{d}t}bigr)^{!2}

]

end{document}