Carlos Eugenio Thompson Pinzón

less info
2,238 reputation
319
bio website blog.chlewey.net
location Bogotá
age 41
visits member for 9 months
seen Jun 19 at 14:25

Human being, or so they say.

Electronics Engineer who has rather worked in Datacom and IT, freelance developer, former IMO contestant who could not solve 1988's 6th problem, and MSc in Mathematics dropout.


Apr
22
awarded  Enlightened
Apr
22
awarded  Nice Answer
Feb
13
revised parametrization of plane in $\mathbb R^3$
TeXing a little
Feb
11
comment Interior of the sum of two sets?
No. Let $A=\mathbb Q\cap[0,1]$, then $\operatorname{int}(\operatorname{cl}(A))=(0,1)$ while $\operatorname{int}(A)=\emptyset$.
Jan
20
reviewed Reject suggested edit on Inequality $\frac{1-3ab}{1-2ac}+\frac{1-3bc}{1-2ba}+\frac{1-3ca}{1-2cb}\geq 0$
Dec
23
comment I need prove about convexity
So, what does the definition of convex function tell you from the identity $x_1 = \mu x+(1-\mu) x_2$ where $\mu\in(0,1)$? (And why we know $\mu\in(0,1)$?)
Dec
23
comment I need prove about convexity
Math.SE is not the place to come to have other people do the homework for you. Do you at least have a definition of convex function?
Dec
23
revised component of a vector $\mathbf a$ onto vector $\mathbf b$
TeXing a little
Dec
23
comment Derivative change sign
By extremum do you mean a local minimum or maximum?
Dec
23
revised how to show $\frac{\partial\hat\sigma}{\partial\hat u}\times\frac{\partial\hat\sigma}{\partial\hat v}$ (cross product)
TeXing the title
Dec
23
reviewed Approve suggested edit on how to show $\frac{\partial\hat\sigma}{\partial\hat u}\times\frac{\partial\hat\sigma}{\partial\hat v}$ (cross product)
Dec
23
comment I need prove about convexity
There are several ways @Chapuller, but I would like to see your work first. What have you tried to solve this problem?
Dec
23
revised determine basis for given vector space
TeXing the image
Dec
23
answered I need prove about convexity
Dec
23
reviewed Reviewed I need prove about convexity
Dec
23
revised I need prove about convexity
TeXing for formality
Dec
23
answered Inequality in triangle involving medians
Dec
23
comment Prove using induction : $n < 3^n$
Write: “R.H.S. $= 3^{p+1}$” and go on.
Dec
23
comment Prove using induction : $n < 3^n$
Hint: What does $3^n$ means when $n=p+1$?
Dec
23
revised Prove using induction : $n < 3^n$
TeXing a little