You are being asked to estimate:Originally Posted byroseh

using 4 equal sub-intervals of . These sub-intervals are:

and .

As we are instructed to use left hand Riemann sums we will approximate the

function on each of these subintervals by its value at the left hand point of

the sub-interval, so:

,

where is the width of the intervals in this case

Hence:

.

This may be compared with the result of doing the integral analytically, which

gives an area of .

RonL