642 reputation
316
bio website lnkd.in/dB_xCjX
location Wernau, Germany
age 29
visits member for 2 years, 10 months
seen 10 hours ago

I am a small time web developer and maintenance programmer toiling in obscurity. I have a BS in Mathematics, and I am working on my Masters.

US-American living in Germany.


Jul
19
comment Doubt in l'Hôpital rule
@anorton You can pull arbitrary constant factors to the outside of a convergent limit.
Jul
8
comment The sum of three consecutive cubes numbers produces 9 multiple
Not to nitpick, but "equations" have equals signs. I don't see an equation anywhere in your question.
Jul
2
comment Why do determinants have their particular form?
The OP didn't ask what the determinant is, they asked why it has the form it has.
Jul
2
awarded  Curious
Jun
16
comment Analytic bijective function is either $az$ or $\frac{a}{z}$
@HaraldHanche-Olsen I withdraw any objections. I read it three times before I posted, but somehow managed to read it wrong anyway.
Jun
16
comment Analytic bijective function is either $az$ or $\frac{a}{z}$
@Arthur Oops, I misread. Sorry. I see that it is fine.
Jun
16
comment Analytic bijective function is either $az$ or $\frac{a}{z}$
Am I missing something? I am not sure it is true for that definition of $\mathbb{C}^*$. 0 doesn't map to anything in that set for $\frac{a}{z}$
Jun
16
awarded  Civic Duty
Jun
16
revised Limit - Could you help me with it
Remove image that was not longer needed. Extra test that had no purpose.
Jun
16
suggested suggested edit on Limit - Could you help me with it
Jun
16
comment Limit - Could you help me with it
If one were being pedantic, isn't this a bit circular, given that integrals are often defined in terms of Riemann Sums? I understand that that would be missing the point (the integral is easier in this case), but it does make this solution a bit unsatisfying, for lack of a better word.
Jun
14
comment Weaker Condition than Differentiability that Implies Continuity
Probably not what you are looking for: Real functions which are convex on an interval are continuous on that interval. They are also differentiable almost everywhere though.
Jun
14
comment How can I prove that a square matrix is invertible if it satisfies this polynomial equation?
Why prove by contradiction?
Jun
9
comment How do I tell if matrices are similar?
Fair enough. I only meant that I think it could be phrased a bit more accessibly. It's possible to explain how to compute the Smith normal form with less technical language.
Jun
9
comment What is integration by parts, really?
I like the adjoint interpretation. It encourages thinking of an integral of a product as a scalar product on $L^2$
Jun
9
comment How do I tell if matrices are similar?
I like the answer, but it does seem a bit level inappropriate for the OP. For instance I suspect the OP would not know what a PID is.
Jun
9
comment How do I tell if matrices are similar?
@MarcvanLeeuwen I think you are right to be cautious. However, since invertibility is generic (the set of singular matrices has measure zero), if we found a singular matrix solution, there should be a non singular matrix in a neighborhood around that.The argument is heuristic perhaps (and not constructive), but I think it is at least reasonable.
Jun
9
comment How to explain the perpendicularity of two lines to a High School student?
-1 link only answer in a foreign language.
Jun
9
comment How to explain the perpendicularity of two lines to a High School student?
Most highschool students who haven't had any trigonometry aren't going to know what a scalar product is.
Jun
5
comment 'Obvious' theorems that are actually false
I remember finding it amazing the first time I did this calculation .