But what formula did you use. Keep in mind that I am in Pre-Calc
The vertical asymtotes occur where tan(x-pi/6) is zero (and so the cot goes
to infinity), which are the points where x-pi/6=n pi, n=0, +/-1, +/-2, ....
RonL
(and checking by ploting the graph of tan(x-pi/6) and or cot(x-pi/6))