722 reputation
317
bio website stackoverflow.com/users/…
location Netherlands
age 18
visits member for 2 years, 5 months
seen 6 hours ago

Programmer, math student.


Dec
15
comment Combinatorics in a Party.
Exactly. I agree with @drhab and I think OP misunderstood the question.
Nov
19
comment Differentiability of a function on $\mathbb R$ such that $f(x+1)=f(x)$.
I bet you meant "Finally, (c) is clearly false."?
Nov
5
comment Inequality proof by induction, what to do next in the step
It's not extremely easy to see that $$2\left(\sqrt{n+2}-\sqrt{n+1}\right) = \frac{2}{\sqrt{n+2}+\sqrt{n+1}},$$ though.
Oct
19
comment Let $T : V \rightarrow V$ be a linear operator. If $T^n = O_V$ for some $n \ge 1$, prove that $I_V + T$ is an isomorphism.
Hint: use \left( and \right) for larger brackets when using exponents.
Sep
22
comment How do I simplify $p^8-Q^8$?
Though this is probably what's intended, I'm not sure if factoring symplifies it.
Aug
27
comment Extending primes
Right, but then $73939133$ obviously is not the biggest prime you'll yield.
Aug
27
comment Extending primes
I guess the prime you start with can only have one digit?
Aug
19
comment Proving there are no integer solutions for $3x^2=9+y^3$
Thanks. I would never write a proof like my second one here on an actual contest or exam, but I've seen proofs to other problems that don't go into much detail at all (which I tried to mimic with my second proof).
Aug
15
comment How many ways can $2m$ be represented as the sum of 4 natural numbers $\le m$?
Is this homework? Then please add the homework tag. Also, could you quote the original problem word for word? The question as it is now is a bit vague.
Aug
15
comment team needs 14 runs to win
@mathslover Generatingfuctionology is pretty good.
Aug
14
comment the partial derivative of $f(x,y)=\ln(x+\sqrt{x^2+y^2}), f_x (3,4)$
That's weird, I use it the most. :-------------)
Aug
14
comment the partial derivative of $f(x,y)=\ln(x+\sqrt{x^2+y^2}), f_x (3,4)$
:-------------)
Aug
14
comment the partial derivative of $f(x,y)=\ln(x+\sqrt{x^2+y^2}), f_x (3,4)$
Your first hint is Hint 0 :)
Aug
11
comment the partial derivative of $f(x,y)=\ln(x+\sqrt{x^2+y^2}), f_x (3,4)$
A computer scientist, eh?
Jul
20
comment Is there a formal definition of “Greater Than”
Shouldn't you add that $c$ is nonnegative? Because for all $a,b$ there exists a $c$ such that $b = a + c$, not only when $a \leq b$.
Jul
10
comment Prove that $a^3+b^3+c^3 \geq a^2b+b^2c+c^2a$
@upaudel If I reduce the original problem to something that I can prove, and I show that both problems are equivalent, then by proving the easier problem, then I also proved the original.
Jul
7
comment Prove that $a^3+b^3+c^3 \geq a^2b+b^2c+c^2a$
@user60887 I'm not doing that, I'm trying to reduce it to something that I can prove.
Jun
26
comment Finding the ratio of two sides of a triangle with known angles
I got it, and edited your answer.
Jun
26
comment Finding the ratio of two sides of a triangle with known angles
Thanks, could you add why this result is equivalent to mine?
Jun
22
comment How to solve infinite square root of 1+ itself or: $\varphi=\sqrt{1+\varphi}$
@Leo Factoring it like that does not really work here, but you are right about bringing it all to the left hand side. Do you know the quadratic formula?