A portion of the graph of $y = f(x)$ is given at right:

1. Sketch the rest of the graph if $f$ is even and calculate the area under the curve for $−3 ≤ x ≤ 3$.

   Hint (a):

   If a function is even, it is symmetric about the $y$-axis.

2. Sketch the rest of the graph if $f$ is odd and calculate the area under the curve for $−3 ≤ x ≤ 3$.

   Hint (b):

   If a function is odd, it also has $180^\circ$ rotational symmetry about the origin.