Write the range of the real function f(x)
Question:

Write the range of the real function f(x) = |x|.

Solution:

Given:

(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, ∞) .