7,968 reputation
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bio website linkedin.com/in/gt6989b
location New York, NY
age 36
visits member for 3 years, 3 months
seen Dec 17 at 4:26

Dec
9
comment Evaluate $\int_{-\infty}^\infty \frac{1}{(x^2+1)^3} dx$
@dustin did not see the tag
Dec
9
comment Integrals over a Surface Using Stokes Theorem
What are your thoughts on the problem? Please explain what you tried and we will be happy to provide hints
Dec
9
comment Why is this true? (sum of 2 uniform distributions)
moved the comment into the answer for readability
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
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
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
comment optimization with non smooth constraint
@JesseRJ MATLAB is not a good solver. Maybe CVXOPT? abel.ee.ucla.edu/cvxopt/examples/index.html There are others that are free. The best paid one is CPLEX sold by IBM
Dec
8
comment optimization with non smooth constraint
@JesseRJ Modern optimizers have a special type for that constraint.
Dec
8
comment optimization with non smooth constraint
@JesseRJ are you using linear optimization only, or can you have binary variables?
Dec
8
comment optimization with non smooth constraint
@JesseRJ I don't understand your comment, likely a part got deleted by accident?
Dec
8
comment Find $\lim_{x \to -8} \frac{\sqrt{1 - x} - 3 }{ 2 + \sqrt[3] {x}}$
@omidh Please see the update, can you finish it now? Feel free to accept the solution when you understand it to the end...
Dec
5
comment expected value - two etaps
Likely, etaps means stages and eagle means tail.
Dec
5
comment Find $\lim_{x \to -8} \frac{\sqrt{1 - x} - 3 }{ 2 + \sqrt[3] {x}}$
Do you know derivatives? can you use L'Hospital's rule?
Dec
5
comment Find $\lim_{x \to -8} \frac{\sqrt{1 - x} - 3 }{ 2 + \sqrt[3] {x}}$
PLease exhibit your work on the problem and we will be glad to give some hints. How about expanding the root in the numerator into Taylor series around $x=1$?
Dec
5
comment What am I doing wrong? (using the formula for lowering powers)
@Cherry_Developer Because $\cos(4x)$ is one object, and also $-\cos(4x) \neq cos(-4x)$