sentences:  There will, of course, be some round-off error, but it is a useful sanity test to see that it is acceptably small.When actually filling in the table values, just assume that "x""n" = 0 and "y""n" = "f"(0), and accept the slight difference in layer "n" − 1's area as rounding error.Given an initial (guess at) "x"1, you need a way to compute the area "t" of the tail for which "x" > "x"1.