How to determine if an differential equation is separable?
Any tips on determining if an differential equation is separable. Starting points etc. Also if an differential equation is separable how to go on and find...
Apr 12, 2026 1 VIEWS
Topic: General
5104 Articles 
Probability of getting all four answers right, with true and false in each question
Suppose there are 4 questions in total. Each question has a true/false option. 1) TRUE or FALSE 2) TRUE or FALSE 3) TRUE or FALSE 4) TRUE or FALSE What is...
Apr 12, 2026 1 VIEWS
How many positive integers $n$ are there such that $(7n + 1)$ is a perfect square and $(3n + 1) < 2008$?
How many positive integers $n$ are there such that $(7n + 1)$ is a perfect square and $(3n + 1) < 2008$ ? What I Tried: We have $(3n + 1) < 2008$ $\...
Apr 12, 2026 1 VIEWS
What is the practical difference between abstract index notation and "ordinary" index notation
I understand that in "normal" index notation the indexes can be thought of as coordinates of scalar values inside a tabular data structure, while in the a...
Apr 12, 2026 1 VIEWS
Inscribed Angles/ Central Angles
If $\angle ACB = 40^{\circ}$(see figure), and the area of the circle is $81\pi$, how long is the arc $ABC$? This is how i have approached this problem. Fi...
Apr 12, 2026 2 VIEWS
Regular Group Actions and Functions
An action of a group $G$ on a set $X$ is regular if for any $x,x'\in X$, there exists a unique $g\in G$ with $gx=x'$. (a) Give an example. (b) L...
Apr 12, 2026 1 VIEWS
Parametric Equation of a Circle in 3D Space?
So, my dilemma here is... I have an axis. This axis is given to me in the format of the slope of the axis in the x,y and z axes. I need to come up with a ...
Apr 12, 2026 2 VIEWS
Distinguish *measure* vs. *count* in definition of *continuous* vs. *discrete*
I have to point out that, when analyzing a probabilistic variable, it is more clear to define continuous and discrete in terms of cardinality: discrete: (...
Apr 12, 2026 1 VIEWS
Difference of two binomial random variables
Could anyone guide me to a document where they derive the distribution of the difference between two binomial random variables. So $X \sim \mathrm{Bin}(n_...
Apr 12, 2026 1 VIEWS
Which set is considered to be well defined in set theory?
I just started learning set theory and in my book a lot of questions start with "Let A be the set defined as ...", but it in most cases turns out that the...
Apr 12, 2026 1 VIEWS
Horizontal curve over an arithmetic surface
Im' working on the book of Lang "introduction to arakelov theory". In the 4th chapter "Hodge index and adjunction formula" p. 99 ...
Apr 12, 2026 1 VIEWS
Proving there exists a linear transformation between the basis of one subspace and the vectors of another
If $\{v_1, ..., v_n\}$ is a basis for V and $w_1, ..., w_2$ are vectors in $W$, not necessarily distinct, then there exists a linear transformation $T: V ...
Apr 12, 2026 1 VIEWS