Question:
Write the range of the real function f(x) = |x|.
Solution:
Given:
f (x) = | x |, x ∈ R
We know that
$|x|= \begin{cases}x, & x \geq 0 \\ -x & x<0\end{cases}$
It can be observed that the range of f (x) = | x | is all real numbers except negative real numbers.
∴ The range of f is [0, ∞) .