Let f : [0, 1] → R and suppose that, for all finite subsets of [0,...

Let f : [0, 1] → R and suppose that, for all finite subsets of [0, 1], 0 ≤ x1 < x2 < · · · < xn ≤ 1,

we have |f(x1) + f(x2) + · · · + f(xn)| ≤ 1. Let S := {x ∈ [0, 1] : f(x) ̸= 0}. Show that S is countable

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Expert Solution

Colby Messinger answered 1 year ago

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