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Financial mathematician-beginner.


Jan
23
comment How do I see that $x^5+x-1=(x^2-x+1)(x^3+x^2-1)$
@GrigoryM, of course, you are right, I am only being blind, having not noticed that the two polynomials are identical.
Jan
23
comment How do I see that $x^5+x-1=(x^2-x+1)(x^3+x^2-1)$
Ahh the mistakes one does when dealing with things out of one's comfort zone! Of course, now I feel stupid, thanks.
Jan
23
asked How do I see that $x^5+x-1=(x^2-x+1)(x^3+x^2-1)$
Jan
22
awarded  Popular Question
Jan
21
accepted Standard deviation - a general confusion.
Jan
18
comment Expressing $x^5-2x^3+6x^2+1$ as a sum of powers of $x+2$
Thanks. Horner Scheme often shows up, solving problems that I wouldn't think would be related, seems like one of the tricks I really should have a closer look at.
Jan
18
comment Expressing $x^5-2x^3+6x^2+1$ as a sum of powers of $x+2$
Thanks, that's the trick of course, I guess I really need to work on my Taylor expansion to spot these!
Jan
18
accepted Expressing $x^5-2x^3+6x^2+1$ as a sum of powers of $x+2$
Jan
18
comment Expressing $x^5-2x^3+6x^2+1$ as a sum of powers of $x+2$
Thanks, although that is pretty much the same as using a matrix for that, only imo harder to compute.
Jan
18
asked Expressing $x^5-2x^3+6x^2+1$ as a sum of powers of $x+2$
Jan
18
comment Investigating $\sum_{n=1}^\infty \frac{\log{n}}{n^c}$
Okay, too hasty. Looking at the last series, I need $\epsilon-c<-1$, so $\epsilon<c-1$ should hopefully do the trick.. right?
Jan
18
comment Investigating $\sum_{n=1}^\infty \frac{\log{n}}{n^c}$
How about $\epsilon=1-c$ then?
Jan
18
comment Investigating $\sum_{n=1}^\infty \frac{\log{n}}{n^c}$
I knew there's a catch somewhere, thanks :) The sign was a typo, corrected.
Jan
18
revised Investigating $\sum_{n=1}^\infty \frac{\log{n}}{n^c}$
deleted 3 characters in body
Jan
18
asked Investigating $\sum_{n=1}^\infty \frac{\log{n}}{n^c}$
Dec
6
comment Standard deviation - a general confusion.
I understand the way the expected value of a random variable is computed, not sure what expectation means. Sorry to be asking questions in a field in which I have very little prior education, I hoped there'd be a simple answer inducing an aha! moment.
Dec
6
comment Standard deviation - a general confusion.
Thanks, I am beginning to understand. In real terms (in terms of this question), what does the number 120 mean? I understand the concept of standard deviation, but I am confused by this question in particular.
Dec
6
asked Standard deviation - a general confusion.
Dec
5
comment Evaluating $\lim_{x \to 0^+} (e^x-1)^{\frac{(\tan{x})^2}{\sqrt[3]{x^2}}}$
Just an additional question: does it exist if x goes to zero (i.e. not just from right)?
Dec
5
accepted Evaluating $\lim_{x \to 0^+} (e^x-1)^{\frac{(\tan{x})^2}{\sqrt[3]{x^2}}}$