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Dec
9
revised Why is this true? (sum of 2 uniform distributions)
added 621 characters in body
Dec
9
comment Why is this true? (sum of 2 uniform distributions)
moved the comment into the answer for readability
Dec
9
revised Solve $y''-xy=0$ about the ordinary point $x=0$
edited title
Dec
9
answered Why is this true? (sum of 2 uniform distributions)
Dec
9
revised Finding exact value of trigonometric functions
LaTeX
Dec
9
revised is a number of the below form ever a perfect square
added 6 characters in body
Dec
8
answered Find a closed form for the generating function for each sequence below
Dec
8
comment Find a closed form for the generating function for each sequence below
Are these finite or infinite? (1) seems right to me...
Dec
8
revised Find a closed form for the generating function for each sequence below
added 8 characters in body
Dec
8
comment Prove this relation
i am not saying this suffices to show that (3,5) is unique; i said, showing (3.5) is unique suffices to solve the problem, since we now can assume $y>0$...
Dec
8
comment Prove this relation
Another one is just as easy: since $y^2 \geq 0$, we must have $x>0$, and the problem is symmetric in $y$, i.e. if $(x,y)$ is a solution, then $(x,-y)$ is a solution as well. Hence, let's look for $y \geq 0$ and it suffices to show that $(3,5)$ is a unique solution.
Dec
8
comment Prove this relation
One observation is that $y$ is even if and only if $x$ is even, but if $y=2m,x=2n$ we have $4m^2+2 = 8n^3$, which happens if and only if $2m^2+1 = 4n^3$, which cannot be since LHS is odd while RHS is even. Hence, neither $x$ nor $y$ can be even...
Dec
8
comment Graph Theory triangle (3 colors)
I don't understand. If you properly edge-color $K_n$ with $n$ colors, no intersecting edges can have the same color, so any triangle must have distinct colors?
Dec
8
revised Graph Theory triangle (3 colors)
alter tags
Dec
8
answered Derangement formula; proof by induction
Dec
8
answered A good source for linear algebra on matrices
Dec
8
comment A good source for linear algebra on matrices
So you need something for abstract algebra with examples from linear algebra, or linear agebra theory, like vector spaces?
Dec
8
comment How can I rotate a point 45 degrees counterclockwise around any point?
@Nichols you are likely better off with $x' = x \cos \theta - y \sin \theta$
Dec
8
comment Finding Transformation inverse
@lllll this is only true about linear transformations from $\mathbb{R}^m$ to $\mathbb{R}^n$, you are transforming a function space.
Dec
8
answered How can I rotate a point 45 degrees counterclockwise around any point?