definition of compact support
According to http://mathworld.wolfram.com/CompactSupport.html , A function has compact support if it is zero outside of a compact set. Alternatively, one ...
Published: Sep 06, 2026
Question 39 in Folland's Real Analysis chapter 3
The question "If {$F_j$} is a sequence of nonnegative increasing functions on $[a,b]$ such that $F(x)= \sum_1^\infty F_j(x) < \infty$" for all $x \in [...
Published: Sep 06, 2026
Method of finding a p-adic expansion to a rational number
Could someone go though the method of finding a p-adic expansion of say $-\frac{1}{6}$ in $\mathbb{Z}_7?$
Published: Sep 06, 2026
What does $\mathbb{R}^n \to \mathbb{R}^m$ mean? And what is $\mathbb{R}^n$?
What the does $\mathbb{R^n}$ mean? For example if something says that it is a transformation $T:\mathbb{R}^2 \rightarrow \mathbb{R}^3$. Does that mean tha...
Published: Sep 06, 2026
The set of real numbers is a subset of the set of complex numbers?
So, I was taught that $\mathbb{Z}\subseteq\mathbb{Q}\subseteq\mathbb{R}$. But since the set of complex numbers is by definition $$\mathbb{C}=\{a+bi:a,b\in...
Published: Sep 06, 2026
Finding the Equation of the Ellipse By Completing the Square
I have the following equation of an ellipse: $$5x^2+9y^2+40x=100$$ I need to put it in the form: $$\frac{(x-h)^2}{m^2} + \frac{(y-k)^2}{n^2} =1 $$ I was t...
Published: Sep 06, 2026
How can i apply Absorption law in this expression?
I have this expression: A + A * B * C' I know that i can use the Absorption law in this and the answer is A, but how can i apply that? Thank you.
Published: Sep 06, 2026
why measure theory for probability?
I studied elementary probability theory. For that, density functions were enough. What is a practical necessity to develop measure theory? What is a probl...
Published: Sep 06, 2026
convergence of the series involving log function
I was asked about convergence of summation of $\log(n)/n^2$ and $\log(1+(1/n))/n^2$. I want to use only p series test. Is there any approximation for $\lo...
Published: Sep 06, 2026
Understanding a limiting procedure
Say I have a function $f(x,y)$ that is defined for all $x \leq 0$ except at a single point $x=x_0 \neq 0.$ There exists one representation of the function...
Published: Sep 06, 2026
