Question

When is a function differentiable on an open interval \[(a,b)\]?

Options

• When it is differentiable only at \[a\] and \[b\].

• When it is differentiable at every point of \[(a,b)\].

• When it is continuous at every point of \[(a,b)\].

• When its left-hand derivative is zero at every point of \[(a,b)\].

Answer 1

Differentiability on an open interval requires differentiability at every point within that interval. The endpoints \[a\] and \[b\] are not part of \[(a,b)\].