🍁・general-2

[marsh linden]

the dream

All they needed was to write

not to scale

and it wouldve been perfect

[gentle heath]

wouldn't put it past them honestly

peak OCR

[marsh linden]

standard

we did aqa im pre sure

but ye

all the same

[ashen mist]

• Drinking game: take a shot every time a theorem or proof says "such that", "for all", or "there exists"

[mossy cloud]

Let ε>0 be given

[exotic kite]

🆙 | Coursite ♫ leveled up!

[ashen mist]

Qué

Basta con decir "Let ε>0"

[marsh linden]

Thanks duckduckgo

[gritty oriole]

duckduckgo is sorry, and still loves you

[marsh linden]

I want to like it

I want to keep using it

But it's just worse

[real imp]

makes no sense to use duckduckgo instead of google

why trust one company over another

if the product is better, just use it

[marsh linden]

But one supposedly doesn't store your info

[celest bay]

anytime I google weather town where I live it gives me the town halfway across the country named after our own

on any browser

not salty at all

[gritty oriole]

One browser isn't my big brother

[tranquil canopy]

it does make sense if you want unfiltered results for whatever reason

i use it sometimes when google is being shitty and i want to find something

[grizzled hedge]

Yeh

Eh duck duck go isn’t bad 🤷‍♂️

Also going to images on duck duck go seems a bit better 🤔

Eh idk

[marsh linden]

I've been disappointed so far

[grizzled hedge]

I feel like there should be more search engines

Like there’s lots of browsers, but not too many search engines

[novel garden]

Ugh, I really gotta take a shit rn.

[celest bay]

thanks for sharing

[median trail]

UwU

[celest bay]

edsel this is not an uwu situation lmao

[median trail]

I just realized that my university bought this book, i'm like

there're always copies for me to read because no one uses this platform except me

[tranquil canopy]

i like duck duck go, but i wouldn't make it my default browser

[gritty oriole]

It does the trick for me honestly, apart from when I'm looking to buy something

Google seems to have aced that dep

[tranquil canopy]

i mean search thingie not browser, you get it

[gritty oriole]

oh

[tranquil canopy]

i'm out of it rn

[gritty oriole]

no ok I knew what you meant

[grizzled hedge]

We use that book too edsel

Looks different though

[mossy cloud]

I have the same, yet different book too

[twin bridge]

@gusty ermine

[gusty ermine]

@gusty ermine

number 5 pls

@grim lava Pls help

@abstract scaffold Pls help

@mossy cloud Pls help

[median trail]

I think you can square the x equation and plug it in the y one, then derive

y = (x^2 - 3)^2

then dy/dx = 2 (x^2-3)*(2x) so this is the formula for the tangent line

then plug 9 in this equation x^2 = t

and you'll have => x = 3 when t = 9

dy/dx = 2((3)^2 - 3)(2(3))

dy/dx = 72 ?

oh wait

you need the line tangent

[gusty ermine]

@iron grove

[median trail]

with dy/dx you just have the slope

so you can plug x = 3 in the y formula again

y = (9-3)^2 => y = 36 when x = 3

so you do

(y - 36) = 72(x - 3)

that's the formula to get the equation of the tangent line

[gusty ermine]

You're a genius

[real imp]

Imagine studying

Haha nerds

cries in unemployed

[gusty ermine]

@median trail Muchas gracias ❤️

[median trail]

[gusty ermine]

puedes ayudar mas? aha

[median trail]

yes

[grizzled hedge]

Derivatives r cul

[twin bridge]

well

i wanna cry

[gusty ermine]

how do i do number 6

[real imp]

Burger king foot lettuce

[gusty ermine]

@twin bridge same

[twin bridge]

@median trail do the answer between i was searching for it

respect, sr

[abstract scaffold]

since the parameterised form was y = something

you probably want to have y as the subject as well

but that's just simple expansion and moving terms around

[gusty ermine]

what do you mean have y as the subject as well

[abstract scaffold]

edsel left his answer without y as the subject

[gusty ermine]

Y-intercept formula?

[abstract scaffold]

he just used the formula and never simplified

but simplifying should be straightforward that he didn't go forward

[gusty ermine]

Ohhh

Is this good?

[mossy cloud]

Are you taking AP Calc BC?

There's a formula that you can use to find dy/dx if you find dy/dt and dx/dt

oh yee

Anyways, sorry, I won't be of much help tonight. I gotta write this stupid essay

[gusty ermine]

No it's AB

[median trail]

yes pillow, just leave the y alone

[abstract scaffold]

edsel's method no work, because he has a +/- situation it seems?

[median trail]

oh wait

[abstract scaffold]

+/- 72

or some shit

[median trail]

yes, it's true

let me check

[gusty ermine]

Isn't dy/dx=(dy/dt)/(dx/dt)

[median trail]

im not sure

[mossy cloud]

yes

[gusty ermine]

Oh where did I go wrong

[gusty ermine]

Yes

[median trail]

isn't dy/dt*dt/dx?

ah yeah

[gusty ermine]

I learned that formula

But idk how to use it

[abstract scaffold]

it's just chain rule

solve dy/dt via the y equation

solve dx/dt via the x equation

multiply them together

dt/dx i mean

[gusty ermine]

How do you solve dy/dt

[abstract scaffold]

do you know what dy/dt means?

[gusty ermine]

no haha

[abstract scaffold]

ok, let's go back

do you know what dy/dx means

[gusty ermine]

that's the instantaneous rate of change..?

[abstract scaffold]

the change in y with respect to x

[gusty ermine]

yes

[abstract scaffold]

so dy/dt is change in y with respect to t

[gusty ermine]

yes

but what is t

i don't get the whole thing with parametrization

[abstract scaffold]

t is just a variable, usually time

basically they are not giving you a simple y = f(x) and then simple differentiation

they give you a y=f(t) equation and want you to find dy/dx

but with y=f(t) you can only get dy/dt

[gusty ermine]

yes i got that

[abstract scaffold]

so you use chain rule to find dy/dx in a way with the information you have:

that is:
dy/dx = (dy/dt)/(dx/dt)
or
dy/dx = (dy/dt)*(dt/dx)

@median trail well, ur answer is right, but you didn't justify why you chose the positive answer rather than the negative. using parameterisation doesn't have that issue.

[gusty ermine]

okay i kinda understand that

what is definition of chain rule

i know how to use it but i don't get the concept of it

[abstract scaffold]

when finding dy/dx is too hard

we introduce some other variable like "u" and make it (dy/du)*(du/dx)

"this is equivalent to dy/dx"

[gusty ermine]

so they provide you with y and x equations in respect to t, and you have to figure out the relationship between y and x?

using t?

[abstract scaffold]

yes

[gusty ermine]

oh i see

chain rule is like peeling an onion

[abstract scaffold]

i guess u could see it that way, yes.

you probably want to use the formula you originally wrote down, not the one I wrote, since you have "x" as a subject rather than "t"

my one would require either reciprocals or implicit differentiation

just thought writing it my way would see that it's just chain rule

[gusty ermine]

i see

why did you say what edsel did was not entirely correct?

[abstract scaffold]

he has x^2 = 9 at some point at his working

thus x = +/- 3

[gusty ermine]

oooo

[abstract scaffold]

so he has to use both cases, or justify why one is not legit

[grizzled hedge]

I always thought of the chain file as a “sponge”

Like outer stuff then the inner stuff

But yeah it’s just dy/dx of outer stuff times dy/dx of inner, on and on

[gusty ermine]

so in order to give complete work, i need to work on both 3 and -3? or is there an other way to do it?

I always forget to take derivatives of inner

[abstract scaffold]

just don't use his way, use the chain rule instead

use the parameterisation given and chain rule from there straight away

for complete work for his method, he needed to justify why he chose x = 3 rather than x = -3

and that is quite difficult to justify.

[gusty ermine]

chain rule is dy/dx = (dy/dt) / (dx/dt)?

[abstract scaffold]

yes

[gusty ermine]

you're amazing

[abstract scaffold]

splitting dy/dx into a t derivative instead

[gusty ermine]

what would dt be?

1?

[abstract scaffold]

if I were to just give you something like

[median trail]

in the next one you have u/v when you derive this you have to use (u'v-uv')/v^2

[abstract scaffold]

y = 14t

and I asked you to find dy/dt, what would the answer be?

[gusty ermine]

I think I solved the next one but not sure if it's right @median trail

14?

[abstract scaffold]

cool.

[median trail]

i think it's okay

[abstract scaffold]

so back to our equations
y = (t-3)^2 and x = sqrt(t)

find dy/dx = (dy/dt)/(dx/dt)

[gusty ermine]

derivative of t = 1

so woulnd' t it just be like dy/dx?

[abstract scaffold]

what do you mean by derivative of t?

[gusty ermine]

so dy/dt, it is 2(t-3)/1

[abstract scaffold]

so so far you have
dy/dx = 2(t-3)/(dx/dt)

[abstract scaffold]

ok, your there

now read the question again to see what you need to do next

i just realised how to justify x = 3 only for edsel's method, but don't do that way, continue like this.

[abstract scaffold]

remember sqrt() just means positive

[gusty ermine]

??

[abstract scaffold]

but x^2 = 9 means x = +/-sqrt(9)

sqrt(9) is only 3,

[gusty ermine]

OHHHH

[abstract scaffold]

remember the inverse relationship between y = x^2 and y = sqrt(x)

only the positive branch is taken for sqrt(x)

as shown by the absence of the negative sign

[gusty ermine]

i see!!!

[abstract scaffold]

only above the x axis

[gusty ermine]

squareroot of any number cannot be negative

i see

[abstract scaffold]

but when solving a quadratic, you have to put +/- sqrt

[median trail]

when I square an equation and when I use sqrt I need to put +/- sign?

[abstract scaffold]

yes

[median trail]

i always forget this

[abstract scaffold]

simple quadratic

[median trail]

(x+1) = 2, in this case do I need the +/- sign?

[abstract scaffold]

no, you just have x lol

x = 2 - 1 = 1

[median trail]

but let's say i want to square it

[abstract scaffold]

that's why squaring is dangerous, because you introduce more solutions

just like solving

sin(x) + cos(x) = 1

go ahead, square both sides then try and solve, it's possible but you introduce fake solutions.

[median trail]

but my question is, +/- sign is only used when getting rid of squares and sqrts?

[gusty ermine]

Use the

**Q u a d r a t I c

E q u a t I o n**

[abstract scaffold]

so that's why there exists the
auxiliary angle method and the t method

[median trail]

i feel so bad that i'm gonna take differential equations but i forget this simple stuff

[abstract scaffold]

ahaha, good luck with laplace transforms

[median trail]

I already took this class

i passed it

but

in this new uni

i have to take it again

[abstract scaffold]

lol

rip

@gusty ermine u seem right, dont forget to make y the subject.

@median trail yeah, when taking the roots of even powers, e.g. a quadratic or quartic... etc equation, then don't forget the +/- sign.

[abstract scaffold]

looks good

[gusty ermine]

awesome!

[abstract scaffold]

to justify it with the earlier method (without using the parameterisation chain rule)

looking at the original equation x = sqrt(t) no matter what t gets inputted, x will always be non-negative, thus when reaching the line x = +/- 3 , you only can write a one liner saying "only positive x due to x = sqrt(t)"

and then u reach the same answer of y = 72x - 180

the only (t) that can be inputted is non-negative t (if you want to stick to real numbers)

[gusty ermine]

does that need a graph to be a complete evidence?

Is number 6 correct

[abstract scaffold]

yes

[gusty ermine]

is number 7 correct?

[abstract scaffold]

almost

[gusty ermine]

Is this good?

[abstract scaffold]

you forgot u'v

This should be the LHS of your third line

[abstract scaffold]

to be nitpicky on the first line, it should just be d/dx rather than dy/dx

[gusty ermine]

Thank you so much!

[abstract scaffold]

don't forget the factor out the front. derivative of x is 1... but you still have the 5

[abstract scaffold]

what you had was

(dy/dx)*(something) = 0

so dy/dx = 0?

or something = 0?

[abstract scaffold]

you got it :)

leaving it in your form is fine

could facto out the 5 in the donominator like my program did

[gusty ermine]

why do they have x next to y?

like y(x)

[abstract scaffold]

I made it that way, because the program would just identify it as some other variable

if i didn't do that

like, it would treat it as a constant

if i just wrote y

[gusty ermine]

ohh i see

[abstract scaffold]

technically speaking, it should be written out as y(x) as well

but that's a pain, so it's understood by context here that y = y(x)

[gusty ermine]

yes makes sense

Is this correct?

[abstract scaffold]

yes

[gusty ermine]

How about this

[abstract scaffold]

you have the method right, you just can't exactly remember the derivative of arctan

[gusty ermine]

it's -(1/2)x

so derivative of (1/2x)

[abstract scaffold]

yeah, my point was you forgot to carry the 2 down

the x^2 is there, but no 2 to be seen

[gusty ermine]

OHHHH

Thank you

[abstract scaffold]

also, the black part needs to be fixed

[gusty ermine]

arctan x = 1/(1+x^2)

[abstract scaffold]

yes

[gusty ermine]

oh it's 1+

not -

[abstract scaffold]

yes

[gusty ermine]

yay

How do I do number 10???

[abstract scaffold]

there's 3 ways.

1. remembering the formula
2. using algebra solely on the RHS to make differentiation easier
3. take something on both sides and use implicit differentiation

I would use 3.

you could probably do some reciprocal bs with a modified way of 3. but yeah

3. try take the ln of both sides

and see where you get

[gusty ermine]

what is RHS?

[abstract scaffold]

right hand side

[gusty ermine]

do i use logarithm?

[abstract scaffold]

yes

ln or log, whatever notation you use

cos you know how to differentiate log_e pretty easily

[gusty ermine]

what do i do after taking logs?

[abstract scaffold]

implicit diff

[gusty ermine]

I feel like I'm doing something wrong

[abstract scaffold]

take logs first before differentiating

[gusty ermine]

But what is log of Dy/dx?

[abstract scaffold]

that's why you take it before differentiating

or else you get log(dy/dx) which is crazy

[gusty ermine]

What do u mean take logs before differentiating?

Taking logs was the first thing I did

[abstract scaffold]

start with y =

not dy/dx

starting with dy/dx means u are already differentiating

ur way, dy/dx = 4^(-x+3) already means that's your final answer

so u got your notation wrong

Implicit differentiation is just utilising chain rule.

[gusty ermine]

Ohhhhhh

No I still don't get it

I don't get that step

[abstract scaffold]

the one with red, green and blue?

if i just gave you this, you know what to do right?

[gusty ermine]

How can this cancel?

Why does this become 1/y

[abstract scaffold]

do you know what the derivative of log(x) is?

[gusty ermine]

No

[abstract scaffold]

ok, do you know the derivative of e^x?

[gusty ermine]

No

[abstract scaffold]

ok. now i see where the problem is

there's a pretty wacky proof

but if y = e^x

then dy/dx = e^x

so using this fact.

derivative of ln(z) is 1/z, w.r.t z

https://www.khanacademy.org/math/in-in-grade-11-ncert/in-in-class11-differentiation/copy-of-sine-and-cosine-derivatives-ab/v/proof-of-derivative-of-ex

Using the method of e^ln(f)

[iron grove]

[gusty ermine]

Why is this e^y = e^(lnx) instead of e(y)=e(lnx)

[abstract scaffold]

because the latter proves no use

ey = eln(x) sure is a true relationship...

but just multiplying doesn't help me find the derivative

so I decided to exponentiate it

[gusty ermine]

What's the rule for exponentiating? I didn't even know you could do that

[abstract scaffold]

if a = b

then by logic:
c^a = c^b

i can do it with any number i like

but e is very useful in these situations since e^x is easy to differentiate

this rule is useful when trying to figure out something like

if c^2 = c^a then what is a?

[gusty ermine]

2!

[abstract scaffold]

so yeah, i can add, divide, multiply, subtract, ln, exponentiate, ...

[gusty ermine]

Woah so cool!!

[abstract scaffold]

e and log are inverses of each other

so if i can take log of both sides, why cant I do e^something on both sides?

[gusty ermine]

I see

[abstract scaffold]

the quick and dirty formula is the last line.

but i never remember that formula

i always derive it

[gusty ermine]

I definitely need to put more time and effort into understanding this problem. Thank you @abstract scaffold so much, I cannot thank you enough for your awesomeness and patience. If you wouldn't mind, it's 1:41 am and I need to wake up pretty early tomorrow, I have to go to bed. It has been such a pleasure to learn from you and get your help. I so appreciate you. You're so smart and I have no idea how you do all these complicated math things but you are amazing. I hope you sleep well or have an amazing day, depending on your timezone. It's unbelievable how many hours math is taking but it sure is fun, thanks to you and other great people who are willing to help me understand. Thank you so much and God bless you abundantly.

[marsh linden]

Idk what stage of education you're at panda but I remember first learning about logs in school and for some unknown reason we learned that log is to the base 10. When f14 talks about log, he's referring to ln, or log to the base e

Just making sure you know

[abstract scaffold]

yeah, i looked at his later questions and they all use base e for "log"

[gritty oriole]

U math wizards are amazing

[abstract scaffold]

just wait to like the 22nd of november

and u'll see my crying for failing subjects perhaps

or confused that im graduating fro Bsc:maths

[marsh linden]

Ah good good

[abstract scaffold]

im not maths wizard

[lavish estuary]

humble 14

[median trail]

@abstract scaffold by the way, I looked up the rule for the +/- sign, and in my case a squared the sqrt of x and it's not necessary to put the +/- since by definition

sqrt(x)^(2) = x, and in a math server they explained me why using sqrt when a variable is squared generates two solutions, but this case doesn't

I went to sleep one hour late because I needed to know why this is haha

[abstract scaffold]

yeah, if you explain at the beginning that x = sqrt(t) means your range for x is x>=0 because sqrt(t) can never be negative, then you justify x = + only

[median trail]

yeah hahaha

[abstract scaffold]

but yeah, you should justify why in your working why you did or did not include +/-

because sometimes you have to choose the (-) minus

e.g. x = -sqrt(t) lol

[median trail]

ah well

[gusty ermine]

I just read over the problem regarding ln and I get it more than I did last night but still confused haha

[abstract scaffold]

it's about knowing how to implicitly differentiate ln(y) with respect to x mainly

[gusty ermine]

Y=ln(x)
Dy/dx= 1/x?

[abstract scaffold]

yes, that's wrt x when ln(x)

but we have ln(y)

and we have to implicitly differentiate that

so using "chain rule i suppose"
d(ln(y))/dx = (d(ln(y))/dy)*(dy/dx)

= (1/y)*(dy/dx)

[gusty ermine]

What's wrt?

[abstract scaffold]

with respect to

[gusty ermine]

Ohhhhh

Makes sense

I shall conquer this problem

When I get to school

[mossy cloud]

@gusty ermine I don’t think I’ve ever mentioned this, but http://tutorial.math.lamar.edu/Classes/CalcI/CalcI.aspx
is an amazing resource that I used for my study with calculus. I used this resource for my Calc II independent study, but he has topics all the way up to Differential Equations.

Khan academy is also a good resource, but it’s missing some concepts in its AP Calc BC course that college professors would teach in their Calc II classes

[gusty ermine]

@mossy cloud thank you so much!!!

So the problem I was working on, y=4^(-x+3) was not supposed to be assigned to us and my teacher apologized to us for assigning what he had not taught us.

He taught it today but I didn't understand how the functions work because he just gave us functions and did not explain how it came about

[ashen mist]

• take log of both sides

[gusty ermine]

This is what I wrote down today but my teacher did not explain how those functions came about (I know the first one because kind F14 taught me last night) but the other ones are just like how

[ashen mist]

f(x) = b^g(x)
log(f(x)) = g(x)*log(b)
[d/dx]log(f(x)) = (1/f(x))*f'(x) because of chain rule
(1/f(x))*f'(x) = log(b)*g'(x)
f'(x) = f(x) * log(b)*g'(x) = (b^g(x))*log(b)*g'(x)

• replace log with ln. I always say log for base e

[gusty ermine]

That's what F14 was trying to explain to me last night

I need to think about that for a long time

Thank you so much math geniuses

[ashen mist]

• not a genius, but yw anyway

[gusty ermine]

@dusty wave

[dusty wave]

@gusty ermine

[gusty ermine]

@tawdry knot

necesito steps

no solamente answer

[exotic kite]

🆙 | Panquesito leveled up!

[gusty ermine]

21a)

i take inverse and get a derivative out of it?

y=cos x+3x
inverse: x=cosy + 3x

[tranquil canopy]

that's not the inverse

[gusty ermine]

how do you get the inverse

[mossy cloud]

You replace the x and the y

and then solve for the y

You forgot to change one of the x variables to y

[gusty ermine]

ohhh

inverse: x=cos y +3y

[mossy cloud]

Actually, I don’t know how’d you solve for y

That seems a little difficult

[gusty ermine]

yes

isn't this just solving for x?

[mossy cloud]

pretty much

Problem is

You need to solve for x completely

I’m not sure how you can do that

[mossy cloud]

Ohhh

[gusty ermine]

i still don't get it

help

[mossy cloud]

you don’t need to find the inverse of the function

hold on

[gusty ermine]

yes profesor

[mossy cloud]

Oooookay

[gusty ermine]

so i do need to find an inverse

[mossy cloud]

No

[gusty ermine]

i want that blackboard

i might be smart if i have that blackboard

[mossy cloud]

The main property that we want to focus on is the one on the top right

[gentle heath]

blackboards are the shit

[mossy cloud]

That’s what happens when you plug an inverse of a function into the original function

[gusty ermine]

no discriminating the blackboard

composite function?

[mossy cloud]

Yee

So if f(0)=1

g(1)=0

kind of like saying... uhh

It’s reversed, is what I’m saying

I’ll draw a picture hold on, need a new piece of chalk

This is an example of how inverse functions be

I proved this on a previous picture

so, that’s how you’d calculate the derivative of the inverse function

[gusty ermine]

is inverse when graph is reflected over y=x?

@tawdry knot vuelve

[mossy cloud]

Yeah

That’s pretty much it

But sometimes you don’t get the entire graph

You see how I split up the parabola?

[gusty ermine]

yes

i see it

Puedo verla

[mossy cloud]

The differentiation formula came from using the chain rule

[gusty ermine]

what is that

No entiendo eso

how do they go from 2nd step to 3rd step

[mortal dagger]

cos x = y - 3x /arcos() in both sides
arcos(cos (x)) = arcos(y - 3x)
x = arcos(y - 3x)

[mossy cloud]

Is that from your notes? @gusty ermine

[gusty ermine]

no

someone gave that to me

this thing

[mossy cloud]

Oh, that isn’t necessary

[gusty ermine]

how do you take inverse of cos sin tan etc

[mossy cloud]

In this case, I think it’s impossible

[gusty ermine]

😮

[mossy cloud]

Yeah

Put that function into desmos

If you were to reflect it along y=x, the function would fail the vertical line test in so many places

[gusty ermine]

Ohhh

[mossy cloud]

wait nvm

I was making a false conjecture

Let’s just say, it’s difficult to find the inverse

probably possible

But difficult

But you don’t need to do that in this case

Ya just need to know what happens at that particular point

[gusty ermine]

Mi brain exploado

[mossy cloud]

Está bien

[rain ermine]

Desmos is the best

[pale lintel]

Hello/Hola

[grizzled hedge]

Desmos is real cool

[crystal kraken]

Is there a friki de química that can help me

[broken whale]

i uwu chem

@crystal kraken where u at

[pale lintel]

He might be asleep

[ashen mist]

Qué es desmos

[whole rain]

This is just kind of a general question about learning spanish rather than something specific about spanish but: how do I improve in spanish? What should I be doing to be able to actually understand spanish without needing to look up a word? I’m kind of losing motivation for learning languages, and I don’t want to lose it.

[hearty sparrow]

what's something you like to do

@whole rain

for example, if you play video games, you could set them to Spanish
if you like to read, find some books in Spanish (although you'll probably have to start out in a lower reading level than you're used to)

another thing to do is just fill your unoccupied time with Spanish
listen to podcasts in the car
watch TV shows in Spanish

[whole rain]

Hm okay

Those are great ideas, thank you!

[hearty sparrow]

no problem :+1:

[marsh linden]

⊕

Anyone know what ^ that symbol means? I think it's a set theory thing

[abstract scaffold]

XOR?

exclusive or

it can be one or the other, but not both.

https://en.wikipedia.org/wiki/Exclusive_or

@marsh linden

We also use that symbol in network and combinatorial optimisation. It's used to denote flow going forward in maximal flow problems.

[marsh linden]

I see

I feel like I'm trying to learn a new language here

[abstract scaffold]

learning this made me finally realise how redstone works in minecraft

[median trail]

you mean the thing with three sticks that sends redstone signal?

[abstract scaffold]

just redstone construction in general

well, i guess that's heading more into engineering/comp sci

to which i am not any of those

[marsh linden]

so if h is a vector of a's
h⊕a is true if that a isn't in the vector h?

like, I have a specific line im trying to understand but idk if it makes sense posting it bc then id have to explain what every bit means haha

[abstract scaffold]

me no understand whats going on

[severe vortex]

Necesito el contexto

[abstract scaffold]

you can use * to bypass hardcore

i dunno what im doing

[lavish estuary]

@grim lava @gusty ermine https://www.youtube.com/watch?v=8KGFAuyLw2M
https://www.youtube.com/watch?v=72PiK16w4Tc
Interesting videos on Rioplatense Spanish. There's a lot of background noise in the first one though

[grim lava]

[ashen mist]

Creo que el primer hombre es argentino (?) Recuerdo haber visto ese video hace mucho tiempo

[lavish estuary]

Sí y son la misma persona xD

[hearty sparrow]

one thing I saw proposed that ⊕ should be used in mathematics to mean something like this:

x⊕y = 1/(1/x+1/y)

[ashen mist]

Qué

Para mí, es XOR nomás

[hearty sparrow]

como esta foto

[ashen mist]

Idk man, apparently the symbol can represent a direct sum *

[hearty sparrow]

https://youtu.be/sULa9Lc4pck

this is where I saw it

it isn't official, this guy was just using it as shorthand

[fossil cipher]

@severe vortex do you even need those lines?

[severe vortex]

I mean yeah

they're essential

[fossil cipher]

okay

[severe vortex]

I removed the line assigning the DMA error callback in the second paste and it still hard faulted

I think the hard fault actually happens the line after when the DMA stream is enabled

[fossil cipher]

must be

yeah somewhere whenever it starts

have you tried commenting out all those lines in that if statement?

and try them one by one

line 47+

[severe vortex]

I

I'll try it

[fossil cipher]

I haven't used C in a while but are you trying to put int32 into int16?

(uint32_t)hi2s->pTxBuffPtr

uint16_t *pData

[severe vortex]

Lemme check that

like I said not my code

I commented the if statement and it doesn't hard fault now

[fossil cipher]

the whole if statement?

[severe vortex]

actually it still does just later

[fossil cipher]

before if

[severe vortex]

before the if statement it's fine i've already checked those lines

[fossil cipher]

i know

but like if you commented the if statement or just the code inside

Whose code is it?

[severe vortex]

the dude who wrote the library idk

[fossil cipher]

could you send me a link?

[severe vortex]

the second one is from STM's HAL library the first one is written by a dude

and I commented the whole if statement

[fossil cipher]

Are you using just a piece of that library? Or are you importing the whole lib?

[severe vortex]

Whole tjing

Imma be away for an hour or two I need to go to the CDR to get my DNI corrected

Had to get my birth certificate mailed here even though they have it scanned in the system and if my new DNI doesn't come in time I can't take the early finals

I'm kinda mad at everything right now thanks for being so helpful

[fossil cipher]

what's cdr and dni? :D

[severe vortex]

Centro de documentacion rapida

[fossil cipher]

I wasn't helpful at all, the issue could be anywhere tbh

[severe vortex]

Documento nacional de identidad

Naw it's always good to get out of my own head for a bit when I have an issue like this

Or even just have someone to describe the issue to

[fossil cipher]

Yeah

Tho i have to say it is a bit more different than an arduino

[severe vortex]

And now rappi is telling me they've blocked my account so now I can't use them to get cash cause I left my debit card in the atm at the banco nacion and I couldn't get it yesterday cause it was a holiday

Also the CDR only accepts payment with card

[fossil cipher]

You left a cc in an atm?

[severe vortex]

It is different lmao

Yeah it's the 5th time now

[fossil cipher]

lol

that sucks

can't you just use a phone?

[severe vortex]

They know me by name

[fossil cipher]

They just retrieve the card from the atm or they give you a new one?

[severe vortex]

They just take it from the machine

It would be bad if I actually lost it because then they'd have to mail me a new one from the US

[fossil cipher]

Where do you live?

in spain?

or mexico

[severe vortex]

On exchange in Argentina

[fossil cipher]

ooh

yeah

i forgot

You were talking about it the other day with somebody else

[severe vortex]

Yeah

It's just very dumb because they were the ones that fucked up putting my name down

Like even after I showed them they took a bit to fuckin process what was going on

[fossil cipher]

:D

[severe vortex]

Their brain couldn't handle the situation

[fossil cipher]

haha

[severe vortex]

Of someone using their moms last name as a middle name

[fossil cipher]

I would actually be confused too, we don't have middle names

[severe vortex]

It's not that hard just put it next to the first name

Like it is on my passport

Which they saw

When they were writing it down

[fossil cipher]

So if they have only inputs for first name and last name, they just put it in the first name after you real first name ;D

[severe vortex]

Middle names exist here im pretty sure

At least they have the concept of a segundo nombre

But yeah now my university won't let me take my finals until I send them a DNI that matches my passport

[junior thicket]

I think it's just weird to see a last name used as a middle name

is it very noticeable that it is a last name?

[severe vortex]

Yeah it's weird

It's my mom's last name

My last name is my dad's last name

[junior thicket]

I know xd I just mean like, if I saw Carla as a middle name I wouldn't think anything of it, but if I saw something like Rodriguez I'd be like "there's gotta be a mistake"

[severe vortex]

They're the only ones who made a mistake here

I'm just a little mad cause their job is to examine documents

And they couldn't just examine the document a bit closer

My birth certificate is very clear that its a middle name

Like when I pointed out the mistake they were like "ooooohhhhhhh" and looked fucking bewildered

[fossil cipher]

lool

[severe vortex]

It's not rocket science lady it's just how my name is

[junior thicket]

idk it's just what I think might be the issue
for us the concept of using a last name as a middle name is just very unusual since we get to keep two last names

[severe vortex]

There's no calculation it's just what they named me

Yes it's unusual

It's also not confusing

[fossil cipher]

Soo what will you do now?

[severe vortex]

I'm gonna go to the fuckin cdr with my fuckin birth certificate that they already fuckin scanned and have in their system and tell them to correct my fuckin DNI then hope it arrives in a fuckin week because you can't get expedited service on corrections

[fossil cipher]

Do you really have to go there again? Can't you just call them to fix it?

[severe vortex]

This is my second time going

The first time they told me I needed my original birth certificate

[fossil cipher]

oh

tards then

[severe vortex]

Because I guess maybe they scanned the fuckin wrong one when they processed my citizenship

Who the fuck knows

[fossil cipher]

yeah

Okay i won't take more of your time and go deal with their mistakes

[severe vortex]

♥♥

[severe vortex]

I'm at the CDR

Theyre on the phone

Idk why

I guess confirming

How many phone calls does she need to make jesus

So

What the fuuuck

Theyre waiting on a call from Buenos Aires

Have they never corrected a fucking DNI before?

This is an established procedure it's on their website

[severe vortex]

So

The lady who originally filled out the form for my nationality needs to fuckin sign it again

With me present

It can only be her

The lady who originally filled out the form for my nationality needs to fuckin sign it again

[gritty oriole]

https://www.youtube.com/watch?v=HAI39mb3QaI&feature=youtu.be

[pale lintel]

Ok

[gusty ermine]

ty @lavish estuary I'll have a look

[pale lintel]

Hola cómo te sientes cómo te has levantado y tú estás aquí aquí y tu que eres un nativo y español más o español de mandarín y tu que estás muy bien y tú estás en la gramática de inglés

[rain ermine]

is 66wpm good

[ashen mist]

En cuanto al teclear?

No sé qué es el promedio

https://smallbusiness.chron.com/good-typing-speed-per-minute-71789.html

Me pregunto qué es el mío

Me he vuelto lento :(

[glass dragon]

66 doesn't seem that good

[ashen mist]

Amaroq no lo hagas sentir mal

[ornate viper]

Supongo que sí 66wpm es bueno. Yo tecleo 95wpm, pero solo en ingles 😛

I love that the channel description is heavily biased to programmers 😄

[abstract scaffold]

lol, it was originally only meant to be that, then we just unoficially decided to use it as a second #☕・general channel

then maths recently started to take over kinda

[grim lava]

i was actually blown away by how slow the average typer is

[abstract scaffold]

r they including boomers?

[grim lava]

🤷‍♂️

[abstract scaffold]

r they including toddlers?

[grim lava]

ive typed at around 90-100wpm on average since i was in middle school, and seeing how my other classmates type, they type at around 60 which isnt much better tbh

[mossy cloud]

I've never learned to type the "proper way"

Don't use my thumbs or pinkies

Tho I don't type any faster than 80wpm on average tbh

[ashen mist]

*. I don't type "properly", but I'll hit 120-140wpm depending on the text and how tryhard I go

[rain ermine]

Y’all

People are much slower than me trust me

And also my typing technique isn’t proper

[eager wagon]

No he intentado uno de esos desde hace mucho tiempo

[rain ermine]

@glass dragon I’m not that slow

[ashen mist]

Uno de qué

[glass dragon]

No, you're not that slow, but that's also not what you asked

[rain ermine]

Eh ig I’ll improve with time

[glass dragon]

Yes you will

[vestal pine]

lol

[glass dragon]

Get to 85 or so before you become an adult who needs to get a job

Then you can feel confident that your typing speeds are "good"

[eager wagon]

jajaja

[rain ermine]

It amazes me how people type at 1000wpm on their phones and yet they type like 20wpm on computers

[glass dragon]

Why? You don't have to be particularly accurate on a phone

[rain ermine]

Right

[eager wagon]

Escribo más rápido en un PC que en mi móvil 😮

[rain ermine]

But usually my fingers go all over the place

And that’s why I prefer my iPad

I mean I can text but it takes more time because of all the errors I’ll usually make

[vestal pine]

I prefer texting on a phone than an iPad

I’m slower on my iPad

[rain ermine]

I’m not

[eager wagon]

No me gustan mucho las tablets

[rain ermine]

But maybe it’s because I’m used to it

I can type on it like a pc lol

[eager wagon]

Mola 🙂 yo no

jaja

soy como un caracol

[rain ermine]

Well I think it takes practice

Take me for example

I’ve been using iPads since I was around 9

And I’ve gotten used to how to type on them

[vestal pine]

Supongo

[eager wagon]

hm sí

[rain ermine]

I may upgrade to a new iPad in 2023 or something like that

[ashen mist]

Teclear en móvil es difícil para mí

Porque solo uso 2 pulgares

[rain ermine]

Big fingers?

[ashen mist]

Thumb*

[vestal pine]

No me importa para los tabletas

[rain ermine]

Oh I use thumbs too

[glass dragon]

Not me. I either swipe with one thumb or type with both index fingers

[eager wagon]

Escribo en una manera raro en mi teclado del PC, no es la manera normal, pero funciona para mi.. entonces nunca he aprendido teclear en la manera normal 😄

[ashen mist]

Aprendí la manera "correcta" pero la ignoro igual

[median trail]

how do I open ports in my raspberry pi?

[tranquil canopy]

pinza y/o martillo

[ashen mist]

@median trail creo que tenés que empezar un servicio que use ese port

• basically you start a service that listens on port X, and then port X is in listening mode, waiting for a connection (it's open)

• netstat -nlp should give you listening ports, as well as the process that's listening on it. Though you might need admin privileges for the -p option to work

[past harbor]

Alguien sabe de Android?

[ashen mist]

No mucho

[past harbor]

Um..

Estoy intentando poner un valor por defecto en un lugar

y me dice que no hay nada por defecto puesto

[ashen mist]

Estás programando?

[past harbor]

No

es desde la interfaz gráfic

[ashen mist]

Ah

No sé nada de eso :( lo siento

[past harbor]

Pongo algo para que salga ahí debajo

Y me sale que no hay nada

[ashen mist]

La cajita está vacía?

*empty checkbox?

[past harbor]

No

tiene valores dentro

[eager wagon]

☑️

[past harbor]

Lo estoy ejecutando en mi móvil y todo está bien

Simplemente no quiere enseñarme

un valor por defecto

Hay opción 1, 2 y 3

si le das te las enseña y te deja elegir

pero si quieres poner un valor por defecto a la app

dice que no, pone "not set"

Por lo que entiendo de inglés, dice que no hay nada ajustado como valor por defecto

pero no sé

[ashen mist]

Pero no hay un checkmark

A menos que entienda mal

[past harbor]

si pones el check a "true"

no te deja poner un valor por defecto

Leí que esta opción está rota en Android y que la deben de arreglar en la nueva actualización

pero mi profesor no sé cómo lo hizo y le funciono

[ashen mist]

Digo, si ponés el check a defaultValue

Ah ok

[past harbor]

quizás me espere a hablar con él

pero si no hago este ejercicio, no puedo hacer el siguiente

[ashen mist]

:(

[past harbor]

Todo me sale mal en esta vida 😄

[ashen mist]

Dijiste que hay una actualización?

[past harbor]

Leí que deberían arreglar todo esto en próximas actualizaciones, simplemente no sé cuándo

[ashen mist]

Ah

[past harbor]

estoy leyendo para que funciona cada atributo

quizás estoy escribiendo donde no es

pone que es el valor por defecto de la preferencia, ya esté activa, no lo esté o ni haya dado donde recoger ese valor

¿No?

[ashen mist]

Uhh me parece que el valor está activo si la persistencia está inactiva, y que el valor también está activo si la persistencia está activa Y la preferencia no se halla en el almacenamiento permanente (?)

El valor por defecto está activo en estos dos casos

1. La persistencia está inactiva
2. La persistencia está activa, pero la preferencia no se halla en el almacenamiento permanente

Es mi interpretación

[past harbor]

mi*

[ashen mist]

No sé, a veces la documentation no es muy entendible

[past harbor]

Vamos, que siempre aparece el valor pero no enseña nada

Tengo más atributos

pero nada tiene que ver con eso

¿Qué significa "Whether the Preference is visible"?

Sé que whether significa "si"

Pero no encaja ahí

[abstract scaffold]

if the preference is able to be seen or not. By default, this is set so that is visible.

[ashen mist]

Determina si la preferencia está visible o no

[past harbor]

¿Whether es un verbo ahí?

[ashen mist]

No

Es que la documentación lo dice mal

[abstract scaffold]

nah, it's kinda just an incomplete sentence

[past harbor]

Ah

[ashen mist]

*Debería decir "determines whether or not the preference is visible"

[past harbor]

Oh

Gracias

[ashen mist]

De nada

[gusty ermine]

Si alguien sabe cómo se hace, pingeadme

[severe vortex]

If I hear the people here say that my middle name is a last name one more time I'm gonna punch something*

It's not MY last name just read the damn birth certificate cause you didn't last time*

[lavish estuary]

Lol

[ashen mist]

@gusty ermine

 log(a/b) = log(a) - log(b)
log(a*b) = log(a) + log(b)
log(a^b) = b*log(a)

[tranquil canopy]

blame english

[gusty ermine]

Thank you! @ashen mist

[ashen mist]

De nada

[tranquil canopy]

while you were doing logarithms, I studied the blade

only acceptable use of this emoji

[lavish estuary]

@past storm echame una mano

[past storm]

Ok

Con qué

[lavish estuary]

Tienes mic?

[past storm]

No puedo hablar ahora, hay mucho ruido

[lavish estuary]

Ah, no pasa nada. Gracias de todos modos :P

[past storm]

[marsh linden]

if anyone knows how to download stereo mix on windows 10

i'll give them a rep

[fossil cipher]

how to download a stereo mix?

what's that?

[marsh linden]

well i want to enable stereo mix

but im unable to

[fossil cipher]

https://www.thewindowsclub.com/windows-10-stereo-mix-not-working-or-picking-audio ?

[marsh linden]

ye i updated my drivers and it didnt help

and the realtek website is terrible

[fossil cipher]

https://www.tenforums.com/drivers-hardware/111899-stereo-mix-no-longer-appears.html#post1389803 ?

https://www.tenforums.com/drivers-hardware/112389-how-enable-stereo-mixer-windows-10-1803-os-17134-112-a.html

Wish i could help, but I don't use windows - would have to download it into a vm.

https://appuals.com/how-to-restore-missing-stereo-mix-on-windows-10/

have you changes your hardware?

changed*

it may be hw specific: https://mediarealm.com.au/articles/stereo-mix-setup-windows-10/

Was it any good?

[marsh linden]

lmao

[fossil cipher]

nice

[marsh linden]

im gonna cry its alright

[fossil cipher]

that's windows for you :D

[marsh linden]

i wanted to be able to record my own computer's sound

but apparently i need this functionality

[fossil cipher]

you should be able to do it without any settings

OBS should be able to do it without any other functionalities i believe

i mean any recording sw should be able

[marsh linden]

i was just using audacity

[fossil cipher]

oh

[marsh linden]

but idk why it wouldnt let me record my own computer

[fossil cipher]

then that may be a different story

[marsh linden]

ye idk

[fossil cipher]

why do you want to record it with audacity?

why can't you use obs?

you can record audio only too i believe

then later edit it in audacity if you need to

[marsh linden]

not for any good reason

its just some recording software i had laying around on my computer

[fossil cipher]

then switch

[marsh linden]

ye ill give it a go

[fossil cipher]

Alright

[marsh linden]

obs works but it only records mp4 which is a pain to convert

im gonna keep looking

[fossil cipher]

are you sure?

you can't export it in different format?

[old charm]

are there any muslims in here? I have a question

[ashen mist]

Qué necesitás

[old charm]

in Islam Isa is Jesus

do you believe that he did the same teachings and stuff

[ashen mist]

• as far as I know, Muslims don't believe he's the son of god. Quran even has Jesus saying he's not

[old charm]

ye I know they dont believe in the trinity and that he's the song of god

[ashen mist]

https://en.m.wikipedia.org/wiki/Jesus_in_Islam

[old charm]

oo

damn

that was helpful

thanks

[ashen mist]

Np

Y no soy musulmán, btw. Si realmente querés hablar con uno, tendrás que esperar

[old charm]

ah okay

I have a test tomorrow

im tryna learn about the prophets

[ashen mist]

Ah, qué clase?

La cultura o historia islámica?

[old charm]

religious education

[ashen mist]

Ah

[old charm]

we have questions on christianity and islam

[ashen mist]

Tomé algunas clases del Islam y cosas relacionadas

Muy interesante

[old charm]

yee it is

[gentle heath]

I never had to know this much about anything for my gcse re lol

[gusty ermine]

For number 7

Is there absolute Max or min? How about local Max and min?

[twin bridge]

I lost my math notebook xd

[gusty ermine]

#41

Pls help

[mossy cloud]

@gusty ermine #7 does not have an absolute max or min

[gusty ermine]

But it has locals, right?

[mossy cloud]

No local max/mins either

For that to happen, there must be a critical point

and #41, you just need to find a point on e^x where the tangent line has a y-intercept at y=0

[hearty sparrow]

so

[broken whale]

hi

[hearty sparrow]

what's the deal

[broken whale]

im dying

[hearty sparrow]

ah

fun

[broken whale]

so

for law of cosines

yknow how it gives u all tje solutions

[hearty sparrow]

yeah

[broken whale]

but the law of sines dowsnt

[hearty sparrow]

yeah

[broken whale]

so for every question do you havw to use law of cosine

if it says use any method

[hearty sparrow]

not every

[broken whale]

cuz u dont rlly know if ur forgetting an andwrr

[hearty sparrow]

what do the problems look like

are you supposed to find all the sides of a triangle

or all the angles or smth

[broken whale]

a = 12 ft b = 30 ft and A = 20 deg

[hearty sparrow]

ah

[broken whale]

find c

[hearty sparrow]

so

use law of sines to find B

then C will be 180-B-A

[broken whale]

but then

[hearty sparrow]

since it's a triangle

oh little c

[broken whale]

the answer says

[hearty sparrow]

mb

then use law of sines to find c from C

[hearty sparrow]

ohh that kind of deal

[broken whale]

also

how do you

do dis

nvm

[hearty sparrow]

so like

in that case, sinB = 30sin20°/12

and so B = sin^-1(30sin20°/12)

[crystal kraken]

Oh gosh law of sines

[hearty sparrow]

but if you look at the unit circle, except for at the very top, every sine value has two different x values

it's like if you took a horizontal line and slowly started moving it down the circle

it almost always touches two different points

so the sin^-1 on the calculator won't give you both answers

so if A is at the origin and b is the line that slants upwards on both, a can be in either of these positions

a and b and A all have the same values in both of these, but none of the other angles or sides are the same

so unless it's a right triangle, use the law of cosines so that you make sure to get both of these

(also those pictures aren't to scale, I was just using them as an example)

[gusty ermine]

Pls help

@abstract scaffold help pls

Where did i go wrong