Use the sympref function to change the display of the symbolic polynomial:
I noticed that the string function does not update with this change(A = "x + x^2/2 + 1"), but it does if you use the latex command (B = '1+x+\frac{x^2}{2}') which may look better for plot headings.
sympref('PolynomialDisplayStyle','ascend')
titletext = ("$" + latex(T) + '$')
title(titletext,Interpreter='latex')