Which of the following statements must be true if a function is differentiable at ?

MATHEMATICS · Single correct · CBSE · Mathematics · Continuity and Differentiability · Continuity and Differentiability

Problem

Which of the following statements must be true if a function

f

is differentiable at

x=c

? (a)

f''

exists at

x=c

. (b)

f

is continuous at

x=c

. (c)

f'

is continuous at

x=c

. (d)

f

has a horizontal tangent line at

x=c