Resposta
LMVT states that if $f$ is continuous on $[a, b]$ and differentiable on $(a, b)$, there exists $c \in (a, b)$ such that $f'(c) = \frac{f(b) - f(a)}{b - a}$.
Explicação
Rolle's theorem is the special case where $f(a) = f(b)$, guaranteeing at least one stationary point where $f'(c) = 0$.