/SQT/ AKA /QTDDTOT/

Thanks user

A way to reverse this process to be honest. The thought of not only humanity going extinct, but all of life isn't comforting.

Sad!

maybe we will figure out, 10,000 years in the future, how and why gravity works, how to create artificial gravity, and keep stuff "static" kinda.

won't solve the hydrogen problem, but maybe we will figure that out, too.

How do I learn proofs?

memorize them
that's what I do.
I ask what proofs are gonna be on the test and just memorize those

Should I use that Velleman's book?

is there any sensible notion of the image of a functor

does this extend to "higher" morphisms, like natural transformations?

>missed the first two weeks of my precakc course
Is the material easy enough to recover from this?

>precalc courses
I never understood this meme. What kind of third world shithole allows kids to graduate high school without knowledge of precalc

Good ol' burgerland.

Many people left highschool knowing no math beyond algebra or trig.

I'm studying for a statistics midterm tomorrow, and I have a quick question: How the hell would you even begin to do Part b?

There was a similar problem I did a bit ago, where what you had to do was P(X > Y) = P(X - Y > 0), and because X and Y were normally distributed, you could integrate to find that probability. Here, though, it's a discrete probabiilty, so I'm not exactly sure what to do (What would X - Y even mean in this case? I'm thinking it's something like this: for f(X =1 , Y = 2), you would subtract the sum of all values for X = 1 by the sum of all values for Y = 2? )

I'm very lost

On my homework we had this question on it, and I had to look up how to solve it because we just learned how to work with resistors yesterday and I really didn't know how to approach it. The answer seemed reliant on all nodes getting equal current or relied on symmetry. My question is what if the resistors all have different resistance, or if it isn't symmetrical?

Suppose V and W are subsets of a normed vector spaces, with [math]V \cap W = \{0\}[/math], and there are sequences [math]\{v_n\} \in V[/math], [math]\{w_n\} \in W[/math], such that [math]|v_n| \to \infty[/math] and [math]|w_n| \to \infty[/math]. Show [math] |v_n + w_n| \to \infty[/math].

Just add up all the probabilities where x>y. when x=1, the only situation is y=0, so .14
when x=2, the only situations are y=1 and y=0, so .04 and .02
for x=3, we have .03, .02, and .01
Adding them all together, and we have .26, which is less than .5
Intuitively you could explain that P(X>Y) and P(X

Math
en.wikipedia.org/wiki/Kirchhoff's_circuit_laws

Doesnt seem true in general. Take your normed vector space to be the reals, V={n : n is natural including 0} W={-n: n is natural and 0} and v_n=n, w_n=-n

you have to learn the rules of the matrix.

ODE A+
Linear A+
Calc 3 A+

that's as far as I'm going to go because I'm an engineer.

I'm going to assume the problem is intended to be in terms of sub_spaces_ instead of subsets.

It seems like a more reasonable question and it would mean the sequences can't cancel each other entirely because they have some components going off in different directions.

If suddenly the Earth will be vanished from space, is there a case, then the Moon will fly right into the Sun?

What is R* in algebra?

space of rational numbers

Depends on your skill level. My teacher recommended a minimum of 10-20 hours a week not including class, but including homework. I spent roughly 8 hours and skimmed by with a B. If i spent 15 hours a week it would have been a cake walk.

Real numbers, surely. So you mean it's the same as R^3?

>When n = 3, the set of all such locations is called three-dimensional Euclidean space. It is commonly represented by the symbol R3

en.wikipedia.org/wiki/Three-dimensional_space

How does one study Discrete Mathematics?

what the fuck is sleeping
like why do we have to be comatose and have vivid hallucinations for 8 hours a day

Woah! Look at this math trick Veeky Forums! Literally made my life 100x easier!

What kind of GENIUS could EVER think of that?

reddit.com/r/AskReddit/comments/5u9y0a/what_are_the_most_useful_mental_math_tricks/ddsg6x5/

Depends on the context.
Could be the extended reals.
The real complex numbers etc.

Which part

Prove 11^(n+1)+12^(2n−1) is divisible by 19 for n being an integer equal or larger than 1... This is via induction I'm stuck with trying to figure out how to factor P(n+1) in terms of P(n) + some multiple of 19

Hey I think I did something, but I'm not yet educated in the subject so pls don't bash me

x(n+1)=11[x(n)-12^(2n-1)]+12(2n+1)
if x(n) = 19k
x(n+1)=11[19k-12^(2n-1)]+12(2n+1)
x(n+1)=11.19k-12^(2n-1).11+12(2n+1)
-12^(2n-1).11+12(2n+1) = 12^(2n-1)[-11+144]
12^(2n-1)[-11+144]=19.7.12^(2n-1)

x(n+1)=11.19k+19.7.12^(2n-1)
Therefore X(n+1) is divisible by 19 if X(n) is divisible by 19

Basic proving, set theory, number theory

the first line (although not exactly correct for my question) put me on the right track! Thanks for it!

If suddenly the Earth will be vanished from space, is there a case, then the Moon will fly right into the Sun?

gravity is not instantaneous, just like the speed of light. however, the moon would probably not fly right into the sun, it would more than likely move in an ellipses

So I'm trying to prove whether
[math]\int{0}^{\infty} \frac{x}{x^3 + 1}dx[/math] converges or diverges. I've tried splitting this up into
[math]\int{0}^{1} \frac{x}{x^3 + 1}dx + \int{1}^{\infty} \frac{x}{x^3 + 1}dx[/math]
and then evaluating the second integral.
[math]\frac{x}{x^2 + 1} \geq \frac{x}{x^3 + 1}[/math] for [math]x \geq 1[/math]
Using u-sub, [math]\int{1}^{\infty} \frac{x}{x^2 + 1} = \frac{1}{2} \int{1}^{\infty} \frac{1}{u}du = \frac{1}{2} = \frac{1}{2} \ln \left x^2 + 1 \right = \frac{1}{2} \left \ln \infty - \ln 2 \right = \infty[/math]
Therefore, by the Comparison Theorem, since this diverges, the original function should diverge too. But the book says it converges. What exactly am I doing wrong?

So I got this ODE:

[eqn] t^2y^{\prime} + 2ty - y^{3} = 0 [/eqn]

So I divide by [math]y^{n}[/math] and make the substituion:
[eqn]v = \frac{1}{y^{2}} \implies v^{\prime} = -\frac{2y^{\prime}}{y^{3}} [/eqn]

to get:

[eqn]-\frac{1}{2}t^{2}v^{\prime} +2tv = 1[/eqn]

I try to write this in: [math] y^{\prime} + p(t)y(t) = q(t) [/math] to get

[eqn] v^{\prime} - \frac{4}{t}v = \frac{2}{t^{2}} [/eqn]

But my solution is not correct after applying integrating factor. Where did I go wrong?

No, th

Are there any Veeky Forums approved guides for error propagation/analysis? I've think I've been told a ton of retarded ways by different lecturers throughout uni. Whats the standard?

>Therefore, by the Comparison Theorem, since this diverges, the original function should diverge too.
wrong

Why?

go read what the comparison theorem says

For a continuous function f(x), if a function g(x) >= f(x) for x >= a, if
[math]\int_{a}^{\infty} g(x) dx[/math]
is converging/diverging, then
[math]\int_{a}^{\infty} f(x) dx[/math]
is converging/diverging, respectively

How did this author go from the component values, to the substitution on the next step?

you wrote it down wrong

read the correct statement of the theorem here
tutorial.math.lamar.edu/Classes/CalcII/ImproperIntegralsCompTest.aspx

You need to do a sanity check here. That's not what the comparison theorem says.

Saying f

>Solving the first of these equations for |T_2| and substituting into the second

ty all I needed was someone else to greentext it to me, got it now

don't know why I'm like this

Do the assigned homework, whenever you get stuck watch a video on it ( not khan academy though fuck that pajeet.) if still doesn't come naturally to you work even more problems. If you can't focus do your work in the library.

>won't solve the hydrogen problem, but maybe we will figure that out, too
easy; we'll break some alpha particles to free the protons
of course, one day protons might start decaying; then we'll be fucked

yeah we'll just fix that too. in 10,000 years, we actually create atoms better than the atoms we have now. Protons, neutrons, and electrons all become obsolete for the Omnitron, which will do anything.

>jumbonium will one day be real
god bless

When you think about it, there really is no reason that this isn't possible for the future. We cannot predict what insane discoveries we will have, and when. Like I mentioned earlier, flying was IMPOSSIBLE for all of humanity until just a few years ago. Putting a person on the fucking MOON would blow the mind of Newton, much less the philosophers and physicists of 2000 years prior.

Imagine what, in 5 times the span between Aristotle and now, we can discover. We [humanity] are going to consider ourselves [current day you and me shitposting] pure brainlet retards who know fuck about nothing.

You can define image of a functor F in the same way as you would in Set or any other category: as the universal arrow factoring through F. This gives a monic arrow that can be identified with the subcategory that is its image.

Are subtraction, multiplication, and division just snobby forms of addition?

>as the universal arrow factoring through F
(if it exists)

The multiplicative subgroup of R, i.e. R \ {0}.

What's the proper method to solve this problem?

a line can be specified by a point and a direction

so (1,0,6) is the point and the direction should be perpendicular to the plane, i.e. given by the normal vector of the plane which is (1,3,1)

so the line is (1,0,6)+t(1,3,1)

Define a sequence by:
[math]a_1=2; a_n=2^{a_n}-1[/math]
Is it possible that the sequence is only primes?

do you mean a_n= 2^(a_{n-1}) - 1?

I do indeed. Turns out its an open problem, I didn't realise.

en.wikipedia.org/wiki/Double_Mersenne_number#Catalan.E2.80.93Mersenne_number_conjecture

G-g-guys can you please help a brainlet with this differential calculus question. Have I d-d-done it right?

P1 of 5.

P2 of 5

P3 of 5

P4 of 5

P5 of 5.

I could have fitted it all onto 1 page, but I thought it would be easier for you guys to follow with some working out.

Please help.

I'm gonna simplify S a bit to make it easier, because using the quotient rule when there is only a constant on the bottom is not just a waste of time, but its absolutely unnecessary and annoying especially when asking someone to check your work.
S=9*(100-20L+L^2)/4pi+sqrt(3)L^2/4
S=(900-180L+9L^2+sqrt(3)piL^2)/4pi
dS/dL=(-180+2(9+sqrt(3)pi)L)/4pi=0
-180+2(9+sqrt(3)pi)L=0
2(9+sqrt(3)pi)L=180
(9+sqrt(3)pi)L=90
L=90/(9+sqrt(3)pi)
So you're good.

I'm sorry for that, it's how I was taught to do it.

And thank you!!!
>mfw I got it right

I never use quotient rule, it's a waste of time memorizing it. Instead, if I have a fraction, I convert it to negative exponents and use the product rule. Alternatively, you could just put a 1/(4pi) on the top to replace the 4pi on the bottom. It's just a constant, so when you take the derivative you can forget about it until the end. It may seem like nitpicking, but when you're taking an exam and using the quotient rule in this manner you are wasting energy and time. Keep practicing, and strive for efficiency.

Yes

matter can't be destroyed. dummy

my bad, it's actually the universe monic (or regular monic etc.) factoring through F:

ncatlab.org/nlab/show/image

fite me

who said matter was being destroyed? space will be so spread out that there will be a cold death. no one said anything about matter being destroyed, the energy will be dissipated.

try to read what i said first, doofus. in fact, the "cold death via entropy" theory is the least controversial idea in this thread

bump because the other one hit the bump limit

Best way to correctly teach myself Algebra in a few months?

baby high school algebra?

cimat.mx/ciencia_para_jovenes/bachillerato/libros/algebra_gelfand.pdf

skip everything and just go straight to spivak out of the womb

thats how u separate the brainlets from the real ogs

>archive.org/details/ElementsOfAlgebraLeonhardEuler2015

>"Read Euler, read Euler! He is the master of us all!" ~ Laplace
>"The study of Euler's works remains the best instruction in the various areas of mathematics and can be replaced by no other." ~ Gauss

How do I calculate the required portion of x if I'm given a percentage of what it needs to be?

For example, let's say I'm mixing colors together, and can only mix them in 20/80 portions. Let's say I want to mix 20% of Red with 80% of Blue, and that I have 30ml of Red. How do I calculate how much Blue I need such that the total ml (when both colors are dumped into a container) reflects a ratio of 20 Red:80 Blue?

Equilibrium is not an end point. It is when the forward and reverse reactions product amounts are equal

Can you not plot an ellipse in polar coordinates? When I try in cartesian, it turns out fine, but in polar it becomes a weird peanut shape. How do I do it?

How is that cat alive with only 2 legs?

I only have 2 legs and I've been doing just fine.

How does a commutator reverse the direction of the current in a DC motor? I know what the commutator does, I just can't seem to get my head around how it actually does it.

Euler had no taste. He just messed around with stuff until he stumbled across something.

I need help understanding this statement:

"All groups of prime order are cyclic"

We just learned Lagrange's theorem, which I understand. Does this mean every single non-identity element is the generator? Also, why does have to be a group? Can't an element generate a sequence that isn't a group?

>Does this mean every single non-identity element is the generator?
Obviously you only need one at a time, but yes.

>Also, why does have to be a group? Can't an element generate a sequence that isn't a group?
is not the set of all things you get by applying the group operation to a over and over.
The subgroup generated by a is defined the smallest subgroup of G that contains a.

This is where Lagrange's theorem comes in, since |G| has no divisors this subgroup has to have order |G| (provided you don't be a goober and pick a to be the identity, but |G|>=2 so you aren't forced to do that)