Find the Range f(x)=-3x if x<=0; 3x+4 if x>0

$f (x) = {\begin{cases} - 3 x & x \leq 0 \\ 3 x + 4 & x > 0 \end{cases}$

Step 1

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