Consider the four functions shown below. On the first two, an approximation for $\int_a^b\,f(x)\,dx$ is shown.

1. For graph number 1, Which integration method is shown?
A. midpoint rule
B. left rule
C. right rule
D. trapezoid rule

Is this method an over- or underestimate?
A. over
B. under

2. For graph number 2, Which integration method is shown?
A. right rule
B. midpoint rule
C. left rule
D. trapezoid rule

Is this method an over- or underestimate?
A. under
B. over

3. On a copy of graph number 3, sketch an estimate with $n=2$ subdivisions using the midpoint rule.
Is this method an over- or underestimate?
A. over
B. under

4. On a copy of graph number 4, sketch an estimate with $n=2$ subdivisions using the trapezoid rule.
Is this method an over- or underestimate?
A. under
B. over