4.I.3F

Analysis II | Part IB, 2006

Let VV be the vector space of all sequences (x1,x2,…)\left(x_{1}, x_{2}, \ldots\right) of real numbers such that xix_{i} converges to zero. Show that the function

∣(x1,x2,…)∣=max⁡i⩾1∣xi∣\left|\left(x_{1}, x_{2}, \ldots\right)\right|=\max _{i \geqslant 1}\left|x_{i}\right|

defines a norm on VV.

Is the sequence

(1,0,0,0,…),(0,1,0,0,…),…(1,0,0,0, \ldots),(0,1,0,0, \ldots), \ldots

convergent in V?V ? Justify your answer.

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