Let's consider the fraction:
$$ \frac{1-\mathrm{e}^{-T/4}}{1-\mathrm{e}^{-T}}. $$
What is the most simplified expression of the above expression, I tried factorizing with the half-angle, but I come up with this complicated expression:
$$ \mathrm{e}^{3T/8}\frac{\sinh(T/8)}{\sinh(T/2)}. $$
Put $$e^{-\frac T4}=x$$
the fraction becomes
$$\frac{1-x}{1-x^4}=\frac{1}{1+x+x^2+x^3}$$ $$=\frac{1}{(1+x)(1+x^2)}$$