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1d
comment Find the change of electromotive-force per degree, at 15 degrees, 20 degrees, and 25 degrees.
The derivative of $1$ is zero, but then the coefficient multiplying $t$ is $-0.000814$, so that should be the term not multiplying $(t-15)$ in the derivative.
1d
answered Poker odds: Chances of a straight flush, given H4,H5
1d
comment Multiples of 3 and 5.
The usual name is Pascal's triangle. No rows have every number even, multiples of 3, or multiples of 5 because there are $1$'s at each end. Is that your question (except for the $1$'s at the end)-which rows have every interior element even (then multiples of 3 and separately multiples of 5)? Have you looked at the first few dozen rows to try to figure it out? There is a simple pattern.
1d
revised Values of $w$ while $y$ changes
edited tags
1d
answered Values of $w$ while $y$ changes
1d
answered Find the change of electromotive-force per degree, at 15 degrees, 20 degrees, and 25 degrees.
1d
comment Which one is greater?
A more common way to express this is up-arrow notation so your $\diamond$ is $\uparrow$
1d
comment $n \mid k^2 \land n+1 \mid l^3 \land n+2 \mid m^4 \to n=?$
Is there any way to recognize the more sensible order aside from trying them all?
1d
revised $T(n) = 2T\left(\frac{\log n}{2}\right)+ \theta(n)$
make title match body
1d
awarded  complex-numbers
1d
answered Finding the possible Least Common Multiples of of numbers with Highest Common Factor 8
2d
comment Find the number of items in $10000$ sets of 10 throws each in which you would expect no even numbers.
You could write up the answer and (after a wait) accept it so this doesn't stay unanswered
2d
comment Find the number of items in $10000$ sets of 10 throws each in which you would expect no even numbers.
I agree p(even) gives p(5 even)=2*p(4 even). Now what is the chance in one set of 10 throws you get no evens? Then multiply by 10000 to get the expected value.
2d
reviewed Approve $\frac{1}{2} \int_{a}^{b} f = \int_{a}^{c} f$
2d
comment Can anyone solve this without substitution
You are looking to solve $234k \equiv 1 \pmod {641}$. Do you know about the Extended Eucledean algorithm?
2d
comment Are surreal numbers isomorphic to formal power series?
Duplicate at mathoverflow.net/questions/194747/… by the same poster. It has an accepted answer there.
2d
comment A new way of thinking about $\pi$
From your other activity I see you can write a comprehensible sentence. If you can't make a reasonable point here, I am done.
2d
comment A new way of thinking about $\pi$
We weren't talking about area at all. We were discussing the ratio of the perimeter of a (regular) polygon to the longest chord. This ratio will approach $\pi$ as the number of sides increases. This is the technique used by Archimedes to estimate $\pi$
2d
comment Are surreal numbers isomorphic to formal power series?
The link you give talks about the surreal numbers. Your title says hyperreal numbers, which is a smaller system. Which are you interested in?
2d
comment $N$ perfect logicians wearing hats
I am not sure it is optimal, but suspect so. There might be a way to prove it by considering the information content of the problem, but I don't see it.