Let and be differentiable functions defined on an open interval containing
MATHEMATICS · Multi-part · AP · Calculus AB · Differentiation: Definition and Fundamental Properties · Differentiation: Definition and Fundamental Properties
Problem
Let f and g be differentiable functions defined on an open interval containing x=2, except possibly at x=2 itself. Assume
• x→2limf(x)=0 and x→2limg(x)=0.
• f′(2)=5 and g′(2)=−2.
Answer the following questions about the quotient g(x)f(x).
(a) Explain why the information given so far is insufficient to decide immediately whether x→2limg(x)f(x) exists.
(b) Determine the value of x→2limg(x)f(x) or state that it does not exist, justifying your conclusion.
(c) Based on your result in part (b), indicate whether x=2 is a vertical asymptote for the graph of y=g(x)f(x). Give a brief justification.