735 reputation
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location Maryland, United States
age 46
visits member for 1 year, 9 months
seen Jan 22 at 20:50

Scientist turned systems engineer by day, I enjoy recreational math, esp. mental approximations and properties related to the prime factorization of a number (e.g., # of divisors, powerful numbers, smooth numbers). I'm also interested when half-integers share a property of integers, such as Pronic numbers, which are essentially the squares of half-integers. For something else intriguing, check out the Sacks number spiral.


Dec
25
comment On “familiarity” (or How to avoid “going down the Math Rabbit Hole”?)
I too have had difficulty getting any traction on new areas from sources such as Wikipedia, and moreover am frustrated to see areas I do know explained in ways that will not help a beginner. For an autodidact, sources of free online textbooks are valuable; reddit.com/r/mathbooks is one place to start.
Dec
24
awarded  Yearling
Dec
14
comment $x$ values for $2x + |x| = 3 + |x+1|$
It is OK to leave work for the reader, but you need to state you have not completed the problem lest the OP think you have demonstrated a complete solution.
Dec
13
comment Determinate a continuous function given a few coordinates.
I also like rational polynomials for practical work. They keep the degree of the polynomial down so they are easier to invert, and often the singularity is outside the region of interest, or is a feature of the function you are fitting to.
Dec
13
comment Determinate a continuous function given a few coordinates.
Write a general polynomial of degree one less than the number of points, then create a system of n equations which are the polynomial evaluated at each point. Then solve the system of equations to get the polynomial coefficients.
Dec
13
answered $x$ values for $2x + |x| = 3 + |x+1|$
Dec
10
answered Values of a, b, and c that the curve $y = ax^3 + 3x^2 + bx + cx + e^x$ has one point of inflection?
Dec
10
comment Values of a, b, and c that the curve $y = ax^3 + 3x^2 + bx + cx + e^x$ has one point of inflection?
Given that $e^x$ is positive will drive you to a negative x. Since it won't be too small you can probably use an estimate for $e^x$ around that x.
Dec
4
answered Does every record of the arithmetic derivative of natural numbers occur at a practical number?
Dec
4
awarded  Custodian
Dec
4
reviewed Reviewed Optimization Word Problem, revenue
Dec
2
comment Does every record of the arithmetic derivative of natural numbers occur at a practical number?
For a moment I thought they might be products of primorials (oeis.org/A025487) which is a tighter restriction, but 640 is the first one that is not. I'll have to keep thinking about it.
Dec
2
answered Positively non-positive (from Brilliant.org) Whats wrong with my method?
Nov
28
comment Trigonometry triangles
Did you use c = - 17,500? I get two solutions, around F = 67 and F = - 260, which both work in the original equation.
Nov
28
comment Can we determine which statements are incomplete due to Godel?
Thanks for the clarification.
Nov
28
accepted Can we determine which statements are incomplete due to Godel?
Nov
28
comment Can we determine which statements are incomplete due to Godel?
So I understand your answer as: Yes, it is possible that any of these conjectures are true but unprovable, and No, we cannot know which questions are the unprovable ones.
Nov
28
revised Trigonometry triangles
expanded answer
Nov
28
answered Trigonometry triangles
Nov
28
comment Lower bound for logarithm?
Since we were discussing bounds A "close to" 0, I assumed we were only interested in a bounding function for $x << 1$.