Federico Ramponi
• Member for 11 years, 4 months
• Last seen more than 9 years ago
• Italy

Here is an example of a physical quantity which comes naturally as a complex number. The impedance between two nodes of a linear electrical circuit working in alternate current, which is the ...

I'll add another title (it's a bit on the theoretical side, but still at the introductory level, very readable and definitely worth): Serge Lang, Linear algebra 3rd. ed., Springer

"The natural numbers are as many as the even natural numbers". This statement is trivial and not worth to be named "theorem", but it is rather counterintuitive if you don't know the meaning of "as ...

As far as I know, your definition A prime is an element p such that whenever p divides ab, then either p divides a or p divides b, is the true definition of "prime". The usual one, ... an ...

Here is how you can construct a linear relation for general bounds: If $x$ goes from $a$ to $b$, then $x-a$ goes from $0$ to $b-a$, then $\frac{x-a}{b-a}$ goes from $0$ to $1$, then \$(x-a) \frac{d-c}{...