I want something which would strong my base in quadratic equations, I know most of the general things but haven't really read any international authors books so I am asking for some advice on there .
I have a random variable $X$ which has a standard normal distribution and another variable $Y$ defined as $Y=\begin{cases} X\quad \text{ if }-1\le X\le 1\\ -X \quad \text{ if }|X|>1\end{cases}$. I'm asked to show that $Y$ is also a standard normal and then to discuss $X+Y$
I was just kidding, but really I mean, it seems like the main important thing to keep in mind are same canonical factorizations, like $n^2x^2 - m^2y^2 = (nx+my)(nx-my)$ and all that stuff, plus quadratic formula. Like, that's about all I ever use in quadratics @Iti
I know but I am preparing for an entrance test and they ask some really weird question on it which require more knowledge and then I thought that I need to brush my skills on these two particular topics.
In number theory, a Gaussian integer is a complex number whose real and imaginary parts are both integers. The Gaussian integers, with ordinary addition and multiplication of complex numbers, form an integral domain, usually written as Z[i]. This integral domain is a particular case of a commutative ring of quadratic integers. It does not have a total ordering that respects arithmetic.
== Formal definition ==
Formally, the Gaussian integers are the set
Z
[
i
]
=
{
a
+
b
i
...
A Gaussian integer a + bi is a Gaussian prime if and only if either:
one of a, b is zero and the other is a prime number of the form 4n + 3 (with n a nonnegative integer) or its negative −(4n + 3), or both are nonzero and a2 + b2 is a prime number (which will not be of the form 4n + 3).
I am not sure what is the right phrase for primes in some ring. The definition I was gave is that in a ring $A$, $p\in A$ is prime if $\forall x,y \in A$ such that $p\mid xy$, $p\mid x$ or $p\mid y$.
I don't know how to start.(I arrived at odd expressions but too long ones) and it is complex fo...
@Alessandro We briefly mentioned it last class, since we were talking about game topologies (in our homework I think we're gonna get that the binary game is homeomorphic to the Cantor set)
I probably know the first half hour of a measure theory lecture
Song kinda did starting talking about sigma algebras and additive functions in order to state (without proof) Lebesgue differentiation, which he used to do change of variables
the only modern play I have read is Waiting for Godot, and it amuses me a lot in answering questions like "what's it about?" with "it's a story where nothing happens".
Did some stuff on outer measures, Caratheodory extension, Radon measures, Lebesgue measure, and then gets to integration
It does do a bit on these things called Vitali and Besicovitch coverings, along with density, which I've heard falls under the realm of a subject called "Geometric Measure Theory"
Hm, I see, we took a long detour in measure theory and defined what it means to integrate with respect to a generic measure and then got to the special cases of the Lebesgue and Hausdorff measures
@Alessandro Makes sense, honestly if there's one thing I don't get about this class, it's that they don't just teach measure theory/integration first, it seems like there's a lot you just can't do without it in functional
In abstraction it's not a problem but basically the first half of our functional was toying with $\ell^p$ spaces, and I'm pretty sure we would've had time to do more stuff if we had $L^p$ spaces and stuff like dominated convergence
What'd you do with Fourier analysis? I've only ever seen Fourier series as a neat trick for physicists and, as @Baymax said, the isoperimetric inequality
Not much, we just showed that they exist because of this nice basis of $L^2$, that they converge in the $||\cdot||_2$ norm, that they converge pointwise almost everywhere and then a few tricks calculating the exact values of some series with them
It's true. I hate chemistry but am bound to it by academic endeavours. I need to finish by the 21st and I have two more 'units' left to complete. A unit contains roughly 16 hours of work and can be completed in two days.
@TedShifrin so what are you up to today what are your plans are you writing a new book or discovering a new physical law or inventing the cure for cancer?
Is it possible to show that $\lim_{n\to\infty}(1+1/n)^n=e$ by merely using $\begin{align}e=\sum_{k=0}^\infty\frac{1}{k!} \end{align}$ and the binomial theorem?
You know the partial sums in the Taylor series converge to $e$, then you know that $\lim_{n\to\infty} (1+\frac{1}{n})^n = \lim_{n\to\infty} \sum_{k=0}^n \frac{1}{k!} = e$