Can someone explain intuitively why this is 52 C 5? What does it mean that the "order doesn't matter?" If I wanted to pick 5 cards from a 52 card dec...

Is there an exact or good approximate expression for the expectation, variance or other moments of the maximum of $n$ independent, identically distributed...

I am studying econometrics, but due to my knowledge level I have to down to the basics. Can someone explain what $x^Tx$ does? I understand how calculation...

Consider the differential equation $$y'=y(y-1)(y-2)$$ Which of the following statements is true ? If $y(0)=0.5$ then y is decreasing. If $y(0)=1.2$ t...

is A "no correlation or zero correlation?" if so, does A have more information than B despite both showing no correlation? Because here no correlation on ...

$$f(x)=\ln \left|\frac{x}{1+x^2}\right|$$ I am told the range of f(x) is: $f(x)\le \ln\frac{1}{2}=-\ln2$ but don't know how to get there. I do know $...

How to find the Rank of Operator A, acting in $\mathbb R^{2\times 2} \ $ by the rule: $$AX=\begin{pmatrix} 1 & 1 \\ 0 & 0 \end{pmatrix}X$$ I'...

A number of times, questions have been asked on this website about good books on Algebraic Topology and the responses have been very valuable. However I n...

Just recently I read up something about involutions (functions $f: A \rightarrow A$ such that $f(f(x))=x$, for all $x$ in the domain of $f$), and was wond...

Today in class my teacher wrote something along the lines of: $6^x = 0$ And proceed to heed a response from the class. A few people shouted undefined. So ...