Find Where Undefined/Discontinuous y=tan(x)-1

Set the argument in ${\displaystyle \tan \left(x\right)}$ equal to ${\displaystyle \frac{\pi }{2}+\pi n}$ to find where the expression is undefined.

The equation is undefined where the denominator equals ${\displaystyle 0}$, the argument of a square root is less than ${\displaystyle 0}$, or the argument of a logarithm is less than or equal to ${\displaystyle 0}$.