Find the Range f(x)=x+3 if x>1; x-3 if x

$f (x) = {\begin{cases} x + 3 & x > 1 \\ x - 3 & x \leq 1 \end{cases}$

The range is the set of all valid $y$ values. Use the graph to find the range.

$(- \infty, - 2] \cup [4, \infty)$

Find the Range f(x)=x+3 if x>1; x-3 if x<=1