The function f ( x ) on the interval [0,30] is graphed below. Use a left-hand sum with 3 sub-intervals to estimate the area between the graph of f and the x-axis on this interval.
Breaking the interval [0,30] into 3 sub-intervals gives us sub-intervals of length 10. From looking at the graph we can see that
We add these and multiply by the length of a sub-interval: