# What is the domain and range of y=tan x?

Domain: (theta|theta!=kpi/2, where k is an odd integer)
Range: $\left(- \infty , \infty\right)$
Remember that $\tan = \frac{\sin}{\cos}$ therefore, you will have a vertical asymptope whenever cos=0. Cos=0 every odd multiple of $\frac{\pi}{2}$.