Is f(x)=x*sin(x) uniformly continuous? justify.

please help.

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- Jul 13th 2009, 10:12 AMKat-Mhelp
Is f(x)=x*sin(x) uniformly continuous? justify.

please help. - Jul 13th 2009, 05:03 PMpickslides
Here's my adhoc attempt, please trump in anybody...

$\displaystyle f_1(x) = x$ is uniformly continuous

$\displaystyle f_2(x) = sin(x)$ is uniformly continuous

therefore $\displaystyle f(x) = x\times sin(x) $ is also uniformly continuous - Jul 13th 2009, 05:42 PMKrizalid
You're wrong.

Product of two uniformly continuous functions is not uniformly continuous.

Cheap example: $\displaystyle f(x)=x$ is uniformly continuous and $\displaystyle g(x)=f(x)\cdot f(x)=x^2$ is not uniformly continuous.

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$\displaystyle h(x)=\sin x$ is also uniformly continuous. (Actually Lipschitz.) - Jul 13th 2009, 05:53 PMJose27
- Jul 13th 2009, 05:54 PMKrizalid
No, I was giving another example about another uniformly continuous function.

- Jul 13th 2009, 07:09 PMpickslides
Good point Krizalid, also if you graph the function you can see it is not uniformly continuous.