Q.
The range of function $f(x)=\operatorname{sgn}(\sin x)+\operatorname{sgn}(\cos x)+\operatorname{sgn}(\tan x)+\operatorname{sgn}(\cot x), x \neq \frac{n \pi}{2}(n \in I)$ is
[Note : sgn $k$ denotes signum function of $k$.]
Relations and Functions - Part 2
Solution: