In your case a = 0 and b = 2
To determine the integral use integration by substitution with
which will give
After some simplifications you should come out with
to b) Are you asked to calculate the area between the x-axis and the graph of the function or do you want to evaluate the integral.
In the first case you have to split the domain into 3 parts.
In the second case you have to split the domain into 2 parts.
Draw a sketch of the graph and you'll see why these preparations are necessary.