Edit: I simplified the function using $\textbf{Simplify[...]}$
How can I minimize this function of $x$, where $l$ is a positive constant?
$$\frac{1}{2} \sqrt{\frac{x}{l}+\frac{l}{x}+4 x^2-2}$$
Mathematica:
1/2 Sqrt[-2 + l/x + x/l + 4 x^2]
I tried taking the derivative to find roots, but that didn't work unless I gave a value for $l$. Anyone know how to find an expression (Most likely? Includes $l$). I want to find this function's x-value when it is at its lowest.
If you would like to use Mathematica functions to minimize the function, Minimize[...] will do.
In the future, you will probably have greater success with Mathematica questions on the Mathematica Stack Exchange.