Hmm. It looks like texlabel doesn't do any special processing for fractions. That kind of makes sense; ideally you wouldn't want the labels for your axes to be so tall that they protrude into the visible space of the axes or extend beyond the limit of the figure window.
Since you're working with symbolic expressions, I'd probably just use the latex function. I'll make a symbolic expression:
>> syms a b c x
>> S = solve(a*x^2+b*x+c == 0, x)
S =
-(b + (b^2 - 4*a*c)^(1/2))/(2*a)
-(b - (b^2 - 4*a*c)^(1/2))/(2*a)
Let's convert that to LaTeX and copy it to the clipboard.
>> clipboard('copy', latex(S));
Now open a Live Editor window and in the Insert tab of the Toolstrip click the triangle under the Equation icon. Select LaTeX Equation and paste into the box where you're asked to enter your LaTeX equation code.
Or since you're working in the Live Editor anyway, just run the first two lines of my example in the Live Editor. The output will be formatted in "pretty print" form.
