For a differentiable function

MATHEMATICS · Single correct · AP · Calculus AB · Limits and Continuity · Limits and Continuity

Problem

f

, the derivative is given by

f'(x)=\frac{3x}{x^{2}-9}.

Which statement best describes the behavior of

f

x=3

? (a)

f

has a vertical tangent line at

x=3

. (b)

f

has a horizontal tangent line at

x=3

. (c)

f

is not continuous at

x=3

. (d)

f

is differentiable at

x=3

and

f'(3)=0