Showing a metric space is complete

[chipotleaway]

Homework Statement

Show the space of all space of all continuous real-valued functions on the interval [0, a] with the metric d(x,y)=sup_{0\leq t\leq a}e^{-Lt}|x(t)-y(t)| is a complete metric space.

The Attempt at a Solution

Spent a few hours just thinking about this question, trying to prove it directly from the definition that says a complete metric space is one where every Cauchy sequence in it has a limit in the space.

I started with an arbitrary Cauchy sequence of functions d(x_m, x_n)=sup_{0\leq t\leq a}e^{-Lt}|x_m(t)-x_n(t)|...that's it! I don't know how to find this limit and show that the sequence converges to that.

 

[micromass]

Try to show that your sequence converges pointswise. So show that for every $t$, the sequence $(x_n(t))_n$ converges to some real number which I denote by $x(t)$. Then show that $x$ defined like this is continuous and that $x_n\rightarrow x$ in your metric.