Calculus
0<B≤π20<B\(\le\]\frac{\pi}{2}\)
0≤B≤π20\(\le\) B\(\le\]\frac{\pi}{2}\)
−π2≤B<0-\(\frac{\pi}{2}\]\le\) B<0
−π2≤B≤0-\(\frac{\pi}{2}\]\le\) B\(\le\)0