- #1
julypraise
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Homework Statement
In usual textbooks, what are the meanings of the notations
(1) [itex]\sup_{k\in\mathbb{N}}|x_{k}|[/itex]
(2) [itex]\sup_{x\in [ a , b ] }|f(x)-g(x)|[/itex]
where [itex](x_{k})[/itex] is a real sequence and [itex]f[/itex] and [itex]g[/itex] are real valued functions
Homework Equations
None.
The Attempt at a Solution
The meaning I guessed is that
(1) [itex]\sup_{k\in\mathbb{N}}|x_{k}|=\sup\{|x_{k}|:k\in \mathbb{N}\}[/itex]
(2) [itex]\sup_{x\in[a,b]}|f(x)-g(x)|=\sup\{|f(x)-g(x)|:x\in[a,b]\}[/itex].