Suppose that we have a sequence of norms (‖⋅‖n)n≥1 on a finite dimensional space X such that, as functions from X to R+, they point-wise converge to a limit norm ‖⋅‖∞. Since we are in a finite-dimensional setting, all of the norms are equivalent among them, and, in particular, all of the norms in the sequence are equivalent to ‖⋅‖∞. An implication of this fact is that there is a sequence of constants cn such that
∀n≥1,∀x∈X,‖x‖n≥cn‖x‖∞.
Now, the equivalence constants cn are not necessarily unique, but, since the norms ‖⋅‖n approach ‖⋅‖∞ in the limit, I am wondering how can one prove that they can be chosen to have 1 as a limit (i.e. lim) ?
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