"Give an example of an increasing sequence (fn) of bounded continuous functions from (0,1] to R which converge pointwise but not uniformly to a bounded continuous function f and explain why Dini's Theorem does not apply in this case"
So clearly Dini's Theorem does not apply, as (0,1] is not a closed interval (or compact metric space), but I can't figure out an example.
My first thought is fn(x)=1xn, but this does not converge pointwise to a bounded continuous function, as x=1 is in the interval
My second thought is fn(x)=x1n. This is clearly an increasing sequence of bounded continuous functions (I think?) I believe this converges pointwise to f(x)=1 for all x∈(0,1], but I'm struggling to then show why this doesn't converge uniformly to f(x)=1
How would I do this? Or is then an easier/better example I could use?
Answer
Take fn(x)=e−1nx and f=1.
Note that supx|fn(x)−f(x)|≥|fn(1n)−1|=1−1e.
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