Question

Let A = {x ∈ R : −4 ≤ x ≤ 4 and x ≠ 0} and f : A → R be defined by $f\left(x\right)=\frac{\left|x\right|}{x}$. Write the range of f.

Answer 1

$\because f\left(x\right)=\frac{\left|x\right|}{x}=\frac{\pm x}{x}=\pm 1\forall x\in A,\text{range of}f=\left\{-1,1\right\}.$