/sqt/ Stupid Questions Thread

>Research in animals shows that it might decrease anxiety and have other effects on the body. But phenibut has not been studied in people, so no one knows whether it might work as a medicine.
I don't want to be lab rat

there are Russian studies but whatever mate, if you want to be miserable who am I to stop you.

>post on Veeky Forums
>not ready to make personal sacrifices to the cause of advancing scientific progress
were it not for the laws of this land I'd have slaughtered you where you stand

What's the y intercept of
F (x) = x/x+2 ?

Why do rotting things get warm? Friction?

Why has my consciousness been with this human throughout its life? What attaches my particular consciousness to this particular human?

consciousness is a brain function

With respect to consciousness, how are the brain functions of my 5 year old self, 15 year old self and 25 year old self identical?

optimal temperature for bacteria is a lil' bit higher than human body temperature.

the stream never breaks across the years

in physics they're used to determine systems/get constants to equations
you are trolling or didn't read this

How? There have been drastic changes to my physiology, mind, and identity. What has been physically constant?

>the stream never breaks
Are there analogues to this in other phenomena?

How do the bacteria create an increase in temperature?

When I buy eggs at the grocery store, how come they don’t become chickens if I never eat them?

nobody knows how consciousness works m8
there was recently a guy who was living with 10% or something of his brain because of fluid and he still had full consciousness

I would put it on a metaphysical part at least some what but there's no way to prove what i'm saying

Can't someone give me a quick rundown of Dennett's explanation or something? What about the observable neuroanatomical structures that are constant across one's life and suspected of giving rise to consciousness.

what is the best book to learn geometry from? anyone have recommendations?

[math]f[/math] is a differentiable in its whole domain, which is all real numbers. If [math]A(0,1)∈Cf[/math], calculate the following limit:

[math]\lim_{x\to0}\frac{f(x^2)-1}{x}[/math]

Any tips on how to solve this one?
Thanks.

meant to say differentiable function

define "A(0,1) ∈ Cf"

literally use the definition of derivative

[math]A[/math] is a point, with its coordinates being [math]x=0,y=0[/math], and it's a point that belongs to the graph of [math]f[/math].

[math]y=1[/math]

god damnit it

Then I'll have:

[math]\lim_{x\to0}\frac{f(x^2)-f(0)}{x-0}[/math]

What am I missing here

well you are missing the answer, but do you see how to use the assumption that f is differentiable to evaluate this here limit ?

something like this I suppose?
I can't think of a way to make this equal to [math]f'(0)[/math]

[math]
\lim\limits_{x \to 0} \frac{f(x^2)-f(0)}{x-0} =
\lim\limits_{x \to 0} \frac{f(x^2)-f(0^2)}{x-0} \stackrel{\text{chain rule}}{=}
f'(0^2) (2 \cdot 0) = 0

[/math]

I haven't been taught about chain rule, hence I can't use it, nor use what you've posted, because, even if it's right, if there isn't in my textbook, then it won't count as correct.

The limit in the first post was the first sub-question. The second one is the following:

Prove that:
[math]\lim_{x\to 0}\frac{f^2(2x)-1}{x}=4f'(0) [/math]

Those two must be linked in some way.

Also if it helps, [math]f(x) [/math] needs to be calculated in the next sub-question and its equal to:

[math]f(x)=2-√(x^2+1), x\in\mathbb{R}[/math]

I literally struggled for hours to prove that every rational number has a decimal expansion which starts repeating at some point. And even then I had to look it up on wikipedia. Tell me honestly sci, should I kill myself?

I have to find if this converges or diverges and if it converges where it converges to.

∑(1/⌊log n⌋ - 1/⌊log (n+1)⌋. (Here ⌊x⌋ is the "round down" function, which rounds x down to the nearest smaller integer.)

But the professor didn't specify where n starts, if I try to solve it with n starting at 1 i get a 1/0, with n starting at 2 i also get a 1/0. What am I doing wrong?
I tried finding the partial sum of this since it's a telescoping series but that isn't getting me anywhere.

>But the professor didn't specify where n starts, if I try to solve it with n starting at 1 i get a 1/0, with n starting at 2 i also get a 1/0. What am I doing wrong?
So start at 3

>with n starting at 2 i also get a 1/0.
You shouldn't

the round down of log(2) and log(3) both are 0

Guys I have a Maths and English assessment coming up for a fancy job. Do you know any websites I could you to brush up on my problem solving and writing, please?

>the round down of log(2) and log(3) both are 0
log(3) doesn't round down to 0

Uhhh... yes it does?

Why are you using log with base 10?

When the base is not specified it's assumed that it's 10? Am I wrong?

>When the base is not specified it's assumed that it's 10? Am I wrong?
Usually base e from my experience, either way whatever base b you use just start indexing from where log_b(n)>=1

When was it ever said that x is in R?

In which grain size class is capillarity most EFFICIENT? Clay, Silt or Sand?

Deltas are most common along the highest coast lines?

log base 10 is kid's stuff. Always assume log base e in mathematical contexts.

>yes mom, I am an internet bad guy

Brainlet here.
Writing my bachelor thesis for math, and this is my first real "scientific" paper. When I write definitions and theorems that I got from a book, do I quote them, or just give the citation for them?

But in CS contexts, assume log base 2.

What is the difference between Electricity and Electromagnetism?

magnets, how do they work?

>What's the y intercept of
>F (x) = x/x+2 ?
(0,0)
0/(0+2) = 0

it's true you retard

you seriously don't use lnx when the base is e?

>you seriously don't use lnx when the base is e?
log is standard

who cares nerd. computers are discrete machines and so you will never need any of that calculus shit in computer science

The highest class in which I used [math] \ln [/math] to mean base e was differential equations. After that everyone uses log, and instead of e^x we use exp(x).

Results look much more clearer like that, specially if you do stuff like analytic number theory where loglogloglog is something you see every day. Imagine lnlnlnlnlnln. That looks like shit!

>who cares nerd. computers are discrete machines and so you will never need any of that calculus shit in computer science
Why would anyone use obscure CS notation instead of the mathematical standard?

>computer "science"

>"computer" "science"

amirite?

i don't care, i'm not even american and we don't call it that. our name for it is a combination of the words information and mathematics.
Which IMO makes it more useful for every day life than plain mathematics

I think that's almost too complicated.
What has to happen is that your mom fucks her own father. Then you are your mom's daughter AND sister.
Then your mom goes and gets pregnant with some other guy. You do the same with some other guy.
Then those 2 children get together and have a child.
You are that child's grandmother. Your mom is also that child's grandmother.

Right?

>i'm not even american and we don't call it tha
But you did call it that.

There's multiple solutions. damn..

I know the sticky says "no homework", but /wsr/ couldn't help me.
I tried using the squeeze theorem, but failed to find a lower boundary, that had max f(x) in it. Looking for a "small enough epsilon" didn't get me anywhere.

I think you have to assume f is non-negative valued. Then, for every epsilon there is a delta around argmax f such that f is within epsilon/2 of max f. Then, for sufficiently large n, even the step function with value zero outside the delta-neighborhood of argmax f, and max f - epsilon/2 inside that neighborhood, has this n-th root of the integral within epsilon of max f.
Or something like this.

Hint:
[eqn]\left(\int_a^b f\left(x \right)^n\,\mathrm dx\right)^\frac1n\,=\,M\,\left(\int_a^b \left(\frac{f\left(x\right)}M\right)^n\,\mathrm dx\right)^\frac1n[/eqn]

It goes "Theorem (Author, [Book]):".
One is the Lorentz boost of the other.
Domain wall defects caused by the ferromagnetic order parameter.

Hello Veeky Forums.

What's this symbol called? Context is lines, vectors and linear algebra.

It's the letter L.

[math] \ell [/math]
ell

cursive L

Awesome, thanks.

Not really a stupid question,but whatever

What are the signs of a good computer science program? What are the signs of a bad one?

why does running my space heater cost more than my computer?
the space heater is 1500W and my computer has a 700W psu. this means it takes more energy to run the heater vs the computer right? I would think a computer takes up a lot more energy than a space heater.

Will a person with age-induced hearing loss notice when you shout at him?

The underlying question is this : is partial hearing loss a kind of "dBm filter" where anything below a certain threshold isn't heard, and anything above the threshold is heard in full. Or is it more like a noise reduction filter where any sound will be lowered by x%?

Also note that your computer's PSU isn't drawing 700 watts off the wall at all times. In order for it to draw 700 watts, it must be at full load (unlikely, unless you have a mutli-GPU solution, and even then, it would draw more than 700 watts to compensate for the energy lost during AC to DC conversion).

Good:
* Microprocessors and computer architecture courses
* Program proof courses
* No OOP first year
* No C++ before at least one year of C
* Unix-like systems (a lot better suited for programming)
* Numerical analysis

Bad:
* Proud that the course "The Beauty and Joy of Computing" is over 50% attended by females
* Emphasizes on webdev
* "Don't worry about performances/memory/bandwidth, we've got plenty of resources in CURRENT_YEAR"
* Takes in people with no proficiency in math

If you have more than one class on intro programming, it's shit.
If you have dedicated classes to OOP, web dev, or GUIs; it's shit.
If you're not required to take Computer Architecture, Operating System Theory, and Compilers; it's shit
If you're not required to take Calculus, Linear Algebra, Proofs, (Calculus based) Probability, (Calculus based) Statistics, Combinatorics & Graph Theory, or took watered down versions in the CS department; it's shit.
If you're not required to take Programming Paradigms, Type and Programming Language Theory, Formal Languages & Automata, Computability Theory, and Complexity Theory; it's shit.
If you're don't at least do one of Networking, Databases, or Distributed Computing; it's shit.
If you don't have a capstone project to graduate, it's shit.

>* No C++ before at least one year of C

Fuck off /g/

It converges to 1/⌊log n_0⌋ because it telescopes and -1/⌊log n_f+1⌋ -> 0

C++ is an incredibly complicated language. Learning it without knowing C well is so suicidal only a retarded code monkey like you would want it.

Can someone help me with this? I want to plot the 5 different graphs this function gives on MATLAB, but somehow I only get one on the plot. Thanks.

a=4.73;
b=7.85;
c=11;
d=14.14;
e=17.27;

q=[a b c d e];

syms x;

hold on;
for i=length(q)
f(x)=sinh(q(i)*x)-sin(q(i)*x) - ((sinh(q(i))-sin(q(i)))/(cosh(q(i))-cos(q(i))))*(cosh(q(i)*x)-cos(q(i)*x))^2;
end

fplot(f(x))

>you need to learn everything at once

pure autismo

youtube.com/watch?v=YnWhqhNdYyk

Guaranteed your C++ programs start with `class Program {`.

a=4.73;
b=7.85;
c=11;
d=14.14;
e=17.27;

q=[a b c d e];

f_i=@(i, x) sinh(q(i)*x)-sin(q(i)*x) - ((sinh(q(i))-sin(q(i)))/(cosh(q(i))-cos(q(i))))*(cosh(q(i)*x)-cos(q(i)*x))^2;

hold on;
for i=length(q)
fplot(@(x) f_i(i, x))
end
hold off;

???

thank you but I still get only one graph on the plot

insert "figure;" before the "hold on;"

Haven't done Matlab in a while, but I would be suspicious about "for i=length(q)".
Wouldn't "for i=1:length(q)" be better?

still get only one graph...