Reputation
Next tag badge:
242/100 score
19/20 answers
Badges
12 33 73
Newest
 Good Answer
Impact
~202k people reached

Sep
6
answered Difference between closure of A and A?
Sep
4
answered Complex Numbers - Weird Equation
Sep
3
revised Inequality $(\sum_{k=0}^{2n-1}x^k / k!)(\sum_{k=0}^{2n-1}(-x)^k / k!)\leq1$ for all $x\in\mathbb R$
added 3 characters in body
Sep
3
revised Inequality $(\sum_{k=0}^{2n-1}x^k / k!)(\sum_{k=0}^{2n-1}(-x)^k / k!)\leq1$ for all $x\in\mathbb R$
deleted 21 characters in body
Sep
3
revised Inequality $(\sum_{k=0}^{2n-1}x^k / k!)(\sum_{k=0}^{2n-1}(-x)^k / k!)\leq1$ for all $x\in\mathbb R$
added 7 characters in body
Sep
3
answered Inequality $(\sum_{k=0}^{2n-1}x^k / k!)(\sum_{k=0}^{2n-1}(-x)^k / k!)\leq1$ for all $x\in\mathbb R$
Sep
3
reviewed Leave Closed some important proofs about adjoint operators
Sep
3
reviewed Reopen Determining North-South Line Via Watch Method: Theory & Reason
Aug
31
comment Why do both sine and cosine exist?
In some sense, it's a kind of coincidence, but in another sense it isn't; the reason we care at all about parameterizing circles is precisely that they're symmetric, and the ability to express $\sin$ and $\cos$ in terms of each other is a consequence of that symmetry...
Aug
30
reviewed Leave Closed How to calculate a, b, center of a ellipse with given bonding box of an arc
Aug
29
comment Prove $\sin^2(\theta)+\cos^4(\theta)=\cos^2(\theta)+\sin^4(\theta)$
Yes. One of those factors is identical to the left-hand side; the other one should look familiar for other reasons...
Aug
29
comment Prove $\sin^2(\theta)+\cos^4(\theta)=\cos^2(\theta)+\sin^4(\theta)$
You could factor either side, but factoring the right side will be helpful and factoring the left side will not.
Aug
29
comment Prove $\sin^2(\theta)+\cos^4(\theta)=\cos^2(\theta)+\sin^4(\theta)$
Try it and see! What do you get when you factor the right-hand side as a difference of two squares?
Aug
29
reviewed Approve Prove $\sin^2(\theta)+\cos^4(\theta)=\cos^2(\theta)+\sin^4(\theta)$
Aug
29
answered Prove $\sin^2(\theta)+\cos^4(\theta)=\cos^2(\theta)+\sin^4(\theta)$
Aug
28
reviewed Leave Closed Combinatorial Proof for Binomial Identity: $\sum_{k = 0}^n \binom{k}{p} = \binom{n+1}{p+1}$
Aug
28
comment Has anyone ever explored $(\sin{x})^x$ , $(\cos{x})^x$, etc?
Even defining your integrand is problematic whenever $\cos x < 0$. And even if you restrict yourself to intervals where this doesn't happen, you'll get singularities at the endpoints when $x$ is negative...
Aug
27
revised Is there anything wrong with this proposed proof of the irrationality of Euler's constant?
texifying, cleaning up some typos
Aug
27
reviewed Reopen Recurrence relation for ternary sequence
Aug
26
comment Why is the solution of an ordinary differential equation required to be defined on an interval?
I'll probably write an actual answer later when I have time unless someone else does, but the short version is: you want the solution's domain of definition to be connected, because if it isn't then the "differentialness" of the equation isn't very meaningful.