May
14
revised How to find the closure of the following set?
removing some tex tags that where outside of tex
May
14
comment Visually stunning math concepts which are easy to explain
I think one understands nothing but will believe everything if one looks at this moving picture. That really is good "1st April" joke.
May
14
revised To solve $2\cdot(5^y)-7^x=1$
tex symbol
May
10
comment Would like to know which version of inductive formula is better
This question is about syntax and does not depend on any interpretation V. So it is not specific to a 4 valued logic.
May
10
reviewed Approve suggested edit on locate any bifurcation in the $2D$ system?
May
7
reviewed Approve suggested edit on Functions Question
May
3
reviewed Approve suggested edit on What is the subset of the letters in the word 'numbers'
May
2
answered Algorithms for factoring multivariate polynomials
May
1
revised How to do epsilon delta proof of continuity
changing the proof for the limit of the root
May
1
revised How to do epsilon delta proof of continuity
changing the proof for the limit of the root
May
1
answered How to do epsilon delta proof of continuity
Apr
17
comment Calculate the last digit of $3^{347}$
$$(3^5)^{69} *3^2 =3^{69} *3^2$$
Apr
8
awarded  Custodian
Apr
8
reviewed Approve suggested edit on If $f \in C^\infty$, and $f$ is nonnegative and integrable in $\mathbb{R}$, can I say that $f^\prime$ is integrable?
Apr
3
comment How can a piece of A4 paper be folded in exactly three equal parts?
1) With this method one can fold a letter an arbitrary number of times (if one does not reach physical limits ). So if one wants to fold it in 5 equal parts one first folds it in $2^3=8$ equal parts and the folds along the line through the top corner and the 5th mark. 2) One must use the second dimensions. When folding only parallel to one side one cannot fold into 3 equal parts. It is not possible to partition an interval $[0,1]$ in three equal parts by bisecting . The points that you can construct this way are $0,1$ and points of the form $\frac{n}{2^k}$.
Mar
21
comment What is the probability that the “smartest” of them has IQ score above 120?
"the smartest of them has IQ score above 120" is the opposite of "all of them have IQ score below 120"
Mar
20
comment Basic Math Question equation to equal 21
$6/(1-5/7)$ You have use parantheses. There is no way if you do not use parantheses.
Mar
8
comment How can you measure out six liters of water?
based on the idea of @Kaladin: fill the 9 liter buckte and remove 2 time 4 liter with the 4 liter bucket then 1 liter remains. put this in the tube. so you can fill the tube win an arbitrary integer number of liters
Mar
8
comment Do we need to formally teach the Greek Alphabet?
@Carl Mummert: t was talking about the 20th century. I have the impression that this alphabet is not used often today ( I would have some explanation for this). But maybe my observation is wrong.
Mar
7
comment Limit, 0/0, square roots
My advice did not work :-(