Tenemos la indeterminación de tipo
0/0,
tal que el límite para el numerador es
$$\lim_{t \to \frac{\pi}{2}^+} \cot{\left(t \right)} = 0$$
y el límite para el denominador es
$$\lim_{t \to \frac{\pi}{2}^+} \frac{1}{\log{\left(t \cot{\left(t \right)} \right)}} = 0$$
Vamos a probar las derivadas del numerador y denominador hasta eliminar la indeterminación.
$$\lim_{t \to \frac{\pi}{2}^+}\left(\log{\left(t \cot{\left(t \right)} \right)} \cot{\left(t \right)}\right)$$
=
$$\lim_{t \to \frac{\pi}{2}^+}\left(\frac{\frac{d}{d t} \cot{\left(t \right)}}{\frac{d}{d t} \frac{1}{\log{\left(t \cot{\left(t \right)} \right)}}}\right)$$
=
$$\lim_{t \to \frac{\pi}{2}^+}\left(- \frac{t \left(- \cot^{2}{\left(t \right)} - 1\right) \log{\left(t \cot{\left(t \right)} \right)}^{2} \cot{\left(t \right)}}{t \left(- \cot^{2}{\left(t \right)} - 1\right) + \cot{\left(t \right)}}\right)$$
=
$$\lim_{t \to \frac{\pi}{2}^+}\left(\left(- \cot^{2}{\left(t \right)} - 1\right) \log{\left(t \cot{\left(t \right)} \right)}^{2} \cot{\left(t \right)}\right)$$
=
$$\lim_{t \to \frac{\pi}{2}^+}\left(\frac{\frac{d}{d t} \log{\left(t \cot{\left(t \right)} \right)}^{2} \cot{\left(t \right)}}{\frac{d}{d t} \frac{1}{- \cot^{2}{\left(t \right)} - 1}}\right)$$
=
$$\lim_{t \to \frac{\pi}{2}^+}\left(\frac{\left(\left(- \cot^{2}{\left(t \right)} - 1\right) \log{\left(t \cot{\left(t \right)} \right)}^{2} + \frac{2 \left(t \left(- \cot^{2}{\left(t \right)} - 1\right) + \cot{\left(t \right)}\right) \log{\left(t \cot{\left(t \right)} \right)}}{t}\right) \left(- \cot^{2}{\left(t \right)} - 1\right)^{2}}{\left(- 2 \cot^{2}{\left(t \right)} - 2\right) \cot{\left(t \right)}}\right)$$
=
$$\lim_{t \to \frac{\pi}{2}^+}\left(- \frac{- \log{\left(t \cot{\left(t \right)} \right)}^{2} \cot^{2}{\left(t \right)} - \log{\left(t \cot{\left(t \right)} \right)}^{2} - 2 \log{\left(t \cot{\left(t \right)} \right)} \cot^{2}{\left(t \right)} - 2 \log{\left(t \cot{\left(t \right)} \right)} + \frac{2 \log{\left(t \cot{\left(t \right)} \right)} \cot{\left(t \right)}}{t}}{2 \cot{\left(t \right)}}\right)$$
=
$$\lim_{t \to \frac{\pi}{2}^+}\left(- \frac{- \log{\left(t \cot{\left(t \right)} \right)}^{2} \cot^{2}{\left(t \right)} - \log{\left(t \cot{\left(t \right)} \right)}^{2} - 2 \log{\left(t \cot{\left(t \right)} \right)} \cot^{2}{\left(t \right)} - 2 \log{\left(t \cot{\left(t \right)} \right)} + \frac{2 \log{\left(t \cot{\left(t \right)} \right)} \cot{\left(t \right)}}{t}}{2 \cot{\left(t \right)}}\right)$$
=
$$0$$
Como puedes ver, hemos aplicado el método de l'Hopital (utilizando la derivada del numerador y denominador) 2 vez (veces)