Consider the four functions shown below. On the first two, an approximation for $\backslash (\backslash$int$\_\{$a$\}^\{$b$\}$ f$($x$)$ d x $\backslash )$ is shown.

$($Click on any graph to get a larger version.$)$

$1.$ For graph number $1,$ Which integration method is shown?

A$.$ left rule

B$.$ midpoint 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$.$ left rule

B$.$ midpoint rule

C$.$ right rule

D$.$ trapezoid rule

Is this method an over$-$ or underestimate?

A$.$ over

B$.$ under

$3.$ On a copy of graph number $3,$ sketch an estimate with $\backslash (\backslash$boldsymbol$\{$n$\}=2\backslash )$ subdivisions using the left rule.

Is this method an over$-$ or underestimate?

A$.$ under

B$.$ over

$4.$ On a copy of graph number $4,$ sketch an estimate with $\backslash (\backslash$boldsymbol$\{$n$\}=2\backslash )$ subdivisions using the trapezoid rule.

Is this method an over$-$ or underestimate?

A$.$ under

B$.$ over