Answer
Domain: All real numbers $t$ such that $ t \ne \pi k $ , where $k$ is an integer
Range: All real numbers
Work Step by Step
A cotangent function is not defined at $0, \pi, 2\pi, 3\pi ...$ So it is not defined at $ \pi k $ , where $k$ is an integer.
The range of a cotangent function is all real numbers.
