The function is not defined at and no amount of factoring or other manipulation can eliminate the "division by zero" issue at . Figure 1.4.1(a) and Table 1.4.1(a) give graphic and numeric evidence that the requisite limit is .
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Table 1.4.1(a) Table of values for
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The requisite manipulations are given below. The first equality is valid because , for any nonzero constant . To pass from the second to the third equality, reason that as goes to zero, so also does . Then, to get the fourth equality, set .
That Maple can obtain this same result is clear from the calculation = .