which of the following statements are true?
(a)If $f$ is twice continuously differentiable in $(a,b)$ and if for all $x\in(a,b)$ , $$f''(x)+2f'(x)+3f(x)=0$$, then f is infinitely differentiable in($a,b$).
(b) Let $f\in C[a,b]$ be differentiable in $(a,b)$. If $f(a)=f(b)=0$, then, for any real number $\alpha$ , there exist $x\in(a,b)$ such that $f'(x)+\alpha f(x)=0$.
I am totally clueless.seek your help.