I have
$\frac{\cos(a)}{\sin(a)}= \frac{\cos(b)}{\sin(b-c)}$
Does this imply something? I know that l.h.s. is
$\tan(a)$
And r.h.s. is
$\frac{\cos(b)}{[\sin(b)\cos(c)-\sin(c)\cos(b)]}$
But is there anything else?
$c>b>a$
Also b and a are $pc$ and $qc$ respectively
where $0<q,p<1$