This is not really a homework question, but i've come across this while preparing for a test(adsbygoogle = window.adsbygoogle || []).push({});

1. The problem statement, all variables and given/known data

Let [tex]f:U \subseteq R^n -> R^m[/tex] be a function which is differentiable at [tex]a \in U[/tex], and [tex]u \in R^n[/tex]

It is then stated that it is clear that:

[tex] lim_{t \to 0} \frac{||f(a+t*u)-f(a)-D_f(t*u)||}{||t*u||} = 0 => lim_{t \to 0} \frac{f(a+t*u)-f(a)-D_f(t*u)}{|t|} = 0[/tex]

How do they get this result?

3. The attempt at a solution

I've tried using the epsilon/delta-def of limits but where the first limit is about real numbers, the second is about vectors in the R^m, so im totally confused.

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# Homework Help: How to go from limit of vector norm to 'normal' limit

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