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Sep
11
revised Concluding that a function is not analytic at a point?
edited body
Sep
11
revised Concluding that a function is not analytic at a point?
edited body
Sep
11
comment Vector functions in engineering
open any textbook on electromagnetism or physics in general.
Sep
11
revised Concluding that a function is not analytic at a point?
deleted 13 characters in body
Sep
11
answered Concluding that a function is not analytic at a point?
Sep
10
comment Prove that if $t \geq 0$, then there exists an $n \in \mathbb N$ such that $n − 1 \leq t < n$.
This isn't a proof because it circularly assumes the floor function exists, i.e. that there is an integer less than $x$. Granted, OP has yet to clarify which axioms are useable.
Sep
10
comment Prove that if $t \geq 0$, then there exists an $n \in \mathbb N$ such that $n − 1 \leq t < n$.
@GregoryE: also you need to know how natural numbers are embedded in the reals. What are your axioms for that? What I mean is as an ordered field, the reals have no sense of "integers." For example, you could have a definition of reals as the completion of rationals.
Sep
10
comment Prove that if $t \geq 0$, then there exists an $n \in \mathbb N$ such that $n − 1 \leq t < n$.
from which axioms do you need to prove this? In other words, what's your working definition for the real numbers? This is why someone asked about Dedekind cuts, one of many ways to define the reals.
Sep
9
answered Matrices to the power of $n$ and their reversibility
Sep
9
comment Mean of squared “sum of squared errors”
If you write down the exact definition of $\bar{X}$ it's not so bad after expanding out the product carefully. Also you probably meant to write covariance, not variance (and adjust the product accordingly).
Sep
9
comment A map $f:([a,b], |\cdot|) \to ([c,d], |\cdot|)$ is an isometry if and only if $d-c = b-a$.
@MattPressland: Hopefully OP will actually say what his definition of isometry is for the problem at hand.
Sep
9
answered Expected Value of a Minimum Function using a Beta Distribution
Sep
9
answered A map $f:([a,b], |\cdot|) \to ([c,d], |\cdot|)$ is an isometry if and only if $d-c = b-a$.
Sep
9
answered Am I missing a trick to solving this differential equation?
Sep
8
comment Does uniform convergence depends on the metric?
Can you think of a pair of metrics that are topologically, but not strongly equivalent?
Sep
8
comment Does uniform convergence depends on the metric?
Certainly it remains true for all strongly equivalent metrics to $d$: en.m.wikipedia.org/wiki/Equivalence_of_metrics
Sep
6
awarded  Revival
Sep
6
comment “Waiter's paradox” - what's wrong with this reasoning?
en.m.wikipedia.org/wiki/Missing_dollar_riddle
Sep
5
revised Intuitive understanding of integral of vector valued functions
added 10 characters in body
Sep
5
answered Intuitive understanding of integral of vector valued functions