Two issues to raise regarding TLatex
Here is a MWE
int latextest()
{
TCanvas *c = new TCanvas();
TLatex latex;
latex.SetNDC();
latex.SetTextFont(43);
latex.SetTextSize(20);
TString latexstring;
latexstring.Form("#frac{1}{2}");
latex.DrawLatex(0.1, 0.1, latexstring);
TString latexstring2;
latexstring2.Form("#frac{#int dX}{#int dX}");
latex.DrawLatex(0.1, 0.3, latexstring2);
TString latexstring3;
latexstring3.Form("#frac{#int^{5}_{0} dX}{#int^{5}_{0} dX}");
latex.DrawLatex(0.1, 0.5, latexstring3);
return 0;
}
Problems:

latexstring2
draws the integrals in such a way that the denominator collides with the fraction line 
latexstring3
produces an error:
*ERROR<TLatex>: Missing denominator for #frac
==> #frac{#int^{5}_{0} dX}{#int^{5}_{0} dX}
I am not sure if the second issue is my own mistake or a problem with ROOT latex syntax interpreter.
First issue seems like a (probably) easy fix, or perhaps a workaround somehow? Screenshot below shows problem.