MATHEMATICS · Multi-part · AP · Calculus AB · Limits and Continuity · Limits and Continuity
Problem
A function p is defined for values of x near −1, but p(−1) is not given. The table shows selected, independently rounded values.
x
−1.4
−1.2
−1.05
−1.01
−0.99
−0.95
−0.8
p(x)
7.36
5.28
4.21
4.04
3.96
3.79
3.12
x
−1.4
−1.2
−1.05
−1.01
Absolute rounding error
≤0.02
≤0.02
≤0.01
≤0.005
x
−0.99
−0.95
−0.8
Absolute rounding error
≤0.005
≤0.01
≤0.02
Use the tables to investigate the behavior of p at x=−1.
(a) Estimate x→−1−limp(x) correct to three decimal places. Show numerically how you account for the stated rounding errors in forming your estimate.
(b) Estimate x→−1+limp(x) correct to three decimal places, again addressing the effect of rounding error.
(c) Does x→−1limp(x) exist? Justify your answer with explicit reference to the estimates obtained in parts (a) and (b).
(d) Suppose it is later discovered that the value at x=−0.95 was mistakenly reported too low by 0.04. Re-evaluate your conclusion in part (c), explaining whether it changes and why.