The rectangles in the graph below illustrate a left endpoint Riemann sum for f$($x$)=($x$^(2))/(11)$ on the interval $3,7.$

The value of this left endpoint Riemann sum is

and this Riemann sum is

an underestimate of

$($i$)$ the area of the region enclosed by y$=$f$($x$),$ the x $-$axis, and the vertical lines x$=3$ and x$=7.$

The rectangles in the graph below illustrate a right endpoint Riemann sum for f$($x$)=($x$^(2))/(11)$ on the interval $3,7.$

The value of this right endpoint Riemann sum is

and this Riemann sum is

the area of the region enclosed by y$=$f$($x$),$ the x$-$axis, and the vertical lines x$=3$ and x$=7.$