Exercise 4.3.9

Assume h : R → R is continuous on R and let K = { x : h ( x ) = 0 } . Show that K is a closed set.

Answers

Let ( x n ) be a convergent sequence in K and set x = lim ⁡ x n . Since h is continuous the limit lim ⁡ h ( x n ) = h ( x ) and since h ( x n ) = 0 for all n lim ⁡ h ( x n ) = 0 . therefore h ( x ) = 0 and x ∈ K .

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2022-01-27 00:00
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