712 reputation
316
bio website stackoverflow.com/users/…
location Netherlands
age 18
visits member for 2 years, 5 months
seen 2 hours ago

Programmer, math lover, student.


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?
Jun
22
comment How to solve infinite square root of 1+ itself or: $\varphi=\sqrt{1+\varphi}$
How would you solve for $x$ in $x^2=x+1$?