(a) Prove that if $f^{\prime}(x) \geq M$ for all $x$ in $[a, b],$ then $f(b) \geq f(a)+$ $M(b-a)$
(b) Prove that if $f^{\prime}(x) \leq m$ for all $x$ in $[a, b],$ then $f(b) \leq f(a)+m(b-a)$
(c) Formulate a similar theorem when $|f(x)| \leq M$ for all $x$ in $[a, b]$