Recent content by thofer

If f is continuous the we certainly have \lim_{x\rightarrow a} \lim_{y\rightarrow b} f(x,y) = \lim_{y\rightarrow b} \lim_{x\rightarrow a} f(x,y). But you do not need that much. Consider g(x,y) = \frac{xy}{x^2+y^2}. The function is discontinuous at (0,0), since \lim_{t\rightarrow 0}...

Without condition you're statement is not true, consider \frac{y^2}{x^2+y^2}.

How do you call the function?

Your solution (f(-x)=-f(x)) is correct. Just two remarks: 1. You do not need to say that the function g is a logarithm (and it is not forcibly of base 10). 2. You can proceed as you did to find the answer, that is, you start with f(-x)=-f(x) and try to reduce. But if you want to write it...

Hi JG89 With the definition of \xi_n you can write \xi_n - \xi_{n-1} = s_n - s - (s_{n-1} - s) = s_n - s_{n-1} = \sum_{v=1}^n a_v - \sum_{v=1}^{n-1} a_v = a_n . This gives the first step. Now you can write the sum of the second step as follows: \sum_{v=n}^m (\xi_v - \xi_{v-1})b_v =...