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Let $X=C[0,1]$ and $x,x_{n}\in X,\forall n\in\mathbb{N}.$ Suppose $\forall t\in[0,1],\ x_{n}(t)\rightarrow x(t)$ and $\sup_{n}\left\Vert x_{n}\right\Vert <\infty$. Show that there exist convex combination of $x_{n}$ that converge to $x$ in $X$ uniformly.

It seems to be closed related to the following theorem:

Suppose $X$ is a metrizable locally convex space. If $\{x_{n}\}$ is a sequence in $X$ that converges weakly to some $x\in X$, then $\exists$ a convex combination of $x_{n}$ that converges to $x$ originally.

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    I finished all the details but one thing: how can I prove uniform convergence. It seems that even on the compact set, pointwise convergence does not imply uniform convergence. By the way, I would accept the comments as the answer (should you post it or them), since they are very helpful. Thank you.2012-04-30

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Okay, so the point is to prove weak convergence, then the theorem you mention would automatically give you norm convergence, ie. uniform convergence (hopefully this answers your last question). To do this we notice that since to every functional $l\in C[0,1]^*$ we can associate two Radon measures such that $l(f)=\int fd\mu_1-\int fd\mu_2$, so it's enough to show that $\int x_n d\mu \to \int xd\mu$, but this is just dominated convergence since $\mu$ is finite and $\| x_n\| \leq C$ for some $C$ which does not depend on $n$.