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seen Apr 2 at 6:50

Sep
4
awarded  Yearling
Sep
4
awarded  Yearling
Jun
3
comment Formula for calculating rate drain
I wish I could double-upvote your answer. An excellent explanation of transition to a more natural additive units, plus spoiler-protected answer!
Jan
8
answered Is there any theorem talking about the uniqueness of eigenvector?
Dec
1
comment how to find center of an arc given start point, end point, radius, and arc direction?
System of two quadratic equations is a pain to solve from the scratch. There are better ways...
Nov
7
comment Finding $\lim_{n \to \infty }\sqrt[n]{b^{2^{-n}}-1}$ without L'hopital
IMHO - l`Hopital is one of the simplest methods. It saves you proofs of the form "for each epsilon there exists N such that for every n>N ...". Those usually involve more complex technics
Oct
23
answered Finding $f(0)$ and $f'(2)$ when $f(x+y+z)=f(x)f(y)f(z), \forall x,y,z \in \mathbb{R}$
Oct
23
answered Am I misapplying L'Hopital's rule?
Oct
4
comment Proving a trigonometric identity
Correct, but incomplete. Please see my post
Oct
4
answered Proving a trigonometric identity
Sep
18
comment Complex integral with essential singularity at 0
It seems like it's impossible to expand Exp(1/x) into Laurent series, because it has infinite number of negative degrees of x. I mean, for every n: Exp(1/x) * x^n diverges at x=0.
Sep
18
answered Calculating time taken to get down a slope
Sep
18
comment Is this sum lesser or equal to 2?
@anon: I see now. Thanks.
Sep
18
answered Is this sum lesser or equal to 2?
Sep
15
comment How to construct the Singular Value Decomposition(SVD) of an operator P?
I know nothing about SVD decomposition of an operator. But I'm trying to guess. Operators may be represented in a matrix form (in finite basis), then SVD decomposition of an operator is probably the same as of the matrix. If the basis is infinite, or even non-discrete, then there's probably a generalization of the same process.
Sep
12
comment Triangle whose height and sides are consecutive integers
I thought about this method too. However you made some "shortcuts". (1) You assume that the height is cast on the edge b, i.e. the "middle" edge. It's not obvious that there are other variants. (2) The last part of your solution, it's surprising that you don't use the fact that h should be equal to b-2, you just verify this at the end. OTOH if you substitute b-2 instead of h you'll get *k*=7 directly, it'll also prove that there are no other solutions.
Sep
11
comment Bases of spaces of continuous functions
The question is unclear. There are infinitely many complete bases of continuous functions for a closed interval with defined boundary conditions. OTOH a typical physical question is defined by a boundary condition and a differential equation. Those together do define a concrete basis.
Sep
11
answered How to create 2x2 matrix to rotate vector to right side?
Sep
8
answered Troublesome functional derivative: second term of Euler-Lagrange equation
Sep
8
comment Differential operator acting on the eigenfunctions of a commuting operator
Am I missing something, but [P,Q] is already a sort of a polynomial. [P,Q] = PQ - QP = 0.