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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.
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Solution
\[\because f\left( x \right) = \frac{\left| x \right|}{x} = \frac{\pm x}{x} = \pm 1 \forall x \in A, \text{ range } off = \left\{ - 1, 1 \right\} . \]
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