The graph of $f\left(x\right) = x^{2} − 3x − 4$ is shown at right. Use the graph to solve:

1. $f \left(x\right) = 0$

   Hint (a):

   Where on the graph is $y = 0?$

   Answer (a):

   $x = −1, x = 4$

2. $f \left(x\right) ≥ 0$

   Hint (b):

   Where on the graph are the y-values greater than or equal to 0?

   Answer (b):

   $x ≥ 4 \text{ or } x ≤ −1$

3. $f \left(x\right) ≤ 0$

   Hint (c):

   See part (b).