The above is a result I got using Mathematica for my research.
Assume that $l$ is fixed, and $\Theta\in[-0.005,0.005]$. I found that there is always a threshold $t_0\in(0.59,0.63)$ such that: The output on the right decreases to $-\infty$ as $t\to t_0^-$ and increases to $+\infty$ as $t\to t_0^+$. Also, $t_0$ decreases as $\Theta$ increases.
I want to draw a graph of $t_0$ versus $\Theta$ using Mathematica. But I have no idea how to determine $t_0$ accurately. Any suggestion or help will be much appreciated!