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comment Integer points belonging to two distinct elliptic curves.
Well, that's just the point: in general the intersections will involve non-integers, only in special cases will you have integer roots in common.
37m
answered Does anyone know of a closed form solution to the following integral?
1h
comment Does anyone know of a closed form solution to the following integral?
I believe you need $n \ge 1$ to get convergence.
1h
answered Convergence and Irrationality of $\frac{H_{(n,-n)}}{(n+1)^n}$ as $n$ approaches infinity
3h
comment How many from 0 to 99999
Please explain what you mean.
4h
comment Express $x$ algebraically with no nested radicals
More generally, see math.stackexchange.com/questions/196155/…
4h
comment The pencils in a box of crayons always have the same color
en.wikipedia.org/wiki/All_horses_are_the_same_color
4h
answered What is the difference between these two statements involving minimums of a function?
4h
answered Space of all improper Riemann-integrable functions not closed under products and other operations
4h
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4h
comment How do I solve $2^x + x = n$ equation for $x$?
You might also note that in this case, $2^n \ln 2 > 0$, so only $W_0$ is needed.
4h
comment How do I solve $2^x + x = n$ equation for $x$?
If you're looking for real solutions, $W_0(x)$ is real for $-1/e \le x < \infty$ and $W_{-1}(x)$ is real for $-1/e \le x < 0$. The other branches do not have real values on $\mathbb R$.
5h
answered Integer points belonging to two distinct elliptic curves.
5h
answered Numerical integration of divergent function
5h
comment Recurrence relation involving infinite sequences.
Somewhat more simply, start with any sequence such that $\sum_n n^2 |F(n)| < \infty$ and then adjust $F(0)$, $F(1)$, $F(2)$ so that $\sum_n (-1)^n F(n) = \sum_n (-1)^n n F(n) = \sum_n (-1)^n n^2 F(n) = 0$ (note that the matrix $\pmatrix{1 & 0 & 0\cr -1 & 1 & -1\cr 1 & 2 & 4\cr}$ is invertible, so this can always be done).
5h
revised Does the sum of the reciprocals of composites that are $ \le $ 1
added 6 characters in body
6h
revised Does the sum of the reciprocals of composites that are $ \le $ 1
added 342 characters in body
6h
comment Maximum determinant of $3 \times 3$ matrix
I didn't mean all $0$'s or all $9$'s, I mean each entry is either $0$ or $9$. Consider e.g. the first column, and fix all other entries at the values for some optimal solution. The determinant is a linear function of the matrix elements $a_{11}, \ldots, a_{n1}$. If the coefficient of $a_{i1}$ in this linear function is positive, you maximize the determinant by taking $a_{i1} = 9$. If negative, you maximize the determinant by taking $a_{i1} = 0$. If $0$, it doesn't matter what $a_{i1}$ is, so you may as well take it to be $0$ or $9$.
6h
comment prime number with property same as 653
I'm finding it hard to find a reasonable interpretation of the question in which $653$ is the only small answer.
7h
comment Condition number of $A^TA$
Not quite. You forgot a square. Also, this is assuming the operator norm induced by the Euclidean norm. There are other matrix norms that are used in defining condition numbers.