#help-42

1 messages · Page 69 of 1

calm coralBOT
fringe reef
#

u sub for x+b/2

#

and then it's a standard integral

quick tiger
brazen elbow
quick tiger
fringe reef
#

just make another substitution

quick tiger
#

yeah let me show you

#

i know it will be arctan something

fringe reef
#

yes

quick tiger
brazen elbow
#

leave it be

quick tiger
brazen elbow
#

if there is no information for d just leave it be, its just some constant

brazen elbow
#

tex it out

quick tiger
brazen elbow
#

$\frac1{d^2}\int\frac{\dd u}{\frac{u^2}{d^2}+1}$

#

is this what you meant

#

pay attention to the d, the upright d is different from normal d

quick tiger
#

$\frac{1}{d^2} \int \frac{du}{\left(\frac{u^2}{d^2} + 1\right)}$

potent lotusBOT
#

RulzerFly

quick tiger
#

i meant this

potent lotusBOT
#

∮μ²ƞdS

brazen elbow
#

why take 1/d^2 out?

#

you are making it harder

#

put that back in

quick tiger
brazen elbow
#

just do it

#

$\int\frac{\dd u}{u^2+d^2}$

potent lotusBOT
#

∮μ²ƞdS

brazen elbow
#

this is what you should have

#

like artametra said, do another substitution

quick tiger
#

it's not arctan(u)

brazen elbow
#

d is just a constant

#

treat it like so

#

whats the formula for trig sub that you learned?

quick tiger
brazen elbow
#

yes

quick tiger
#

they gave us this in the lesson

#

$\arctan(u) = \frac{1}{u^2 + 1}$

potent lotusBOT
#

RulzerFly

quick tiger
#

no no

#

$\arctan(u) = \frac{1}{1 - u^2 }$

potent lotusBOT
#

RulzerFly

brazen elbow
#

well you dont exactly need that

#

heres a formula you should use

quick tiger
#

$\frac{d}{du} \arctan(u) = \frac{1}{1 + \tan^2(\arctan(u))}
$

#

$\frac{d}{du} \arctan(u) = \frac{1}{1 + \tan^2(\arctan(u))}$

potent lotusBOT
#

RulzerFly

brazen elbow
#

wait

quick tiger
#

okay

brazen elbow
#

$\int\frac{\dd x}{(x^2+a^2)^n} \to x=a\tan u$

potent lotusBOT
#

∮μ²ƞdS

brazen elbow
#

use this

quick tiger
quick tiger
#

1/d is constant

brazen elbow
quick tiger
#

What the f i mixed everything together.....

quick tiger
#

$\frac{1}{d} \arctan\left(\frac{x + \frac{b}{2}}{d}\right) $

#

$\frac{1}{d} \arctan\left(\frac{x + \frac{b}{2}}{d}\right)$

potent lotusBOT
#

RulzerFly

quick tiger
brazen elbow
#

seems to check out

#

yeah thats correct

quick tiger
quick tiger
brazen elbow
#

not really lol

#

but yeah np

calm coralBOT
#

@quick tiger Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

sturdy haven
#

Hi, i am a bit confused about the process on the right side- i understand why you want to multiply magnitude by sin and cos because the hypotenuse on the bottom will cancel out and you will simply have the x and y components, but how does this work for the 300N vector (the work done on the right) because there isnt really a triangle made here (and i know you could just look at and know its -300,0 but i kinda wanna understand how it works)

pearl dune
#

Better to think in terms of the angle, like the angle of F1 is 60 and the angle of F2 is 180, but if you think of it as a triangle it's effectively a triangle where the 'height'/'opposite' is 0 so the 'hypotenuse' and 'adjacent' merge into a single line

#

Like imagine what happens to the sides of this triangle as theta gets smaller and tends to 0

#

In the context of that diagram in your picture, their angle is measured from the +ve x, so is just 180-theta where theta is the angle in the triangle I drew

#

So as theta becomes 0, the angle in your diagram is 180-0 so just 180

#

Hence you arrive at the derivation of F2

sturdy haven
#

ok

#

yeah i think that makes sense ty

pearl dune
#

Np!

calm coralBOT
#

@sturdy haven Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

crystal axle
calm coralBOT
crystal axle
#

<@&286206848099549185>

remote mural
#

do you know what a circle is

crystal axle
#

uhh no

#

yes i do

remote mural
#

what about the center of a circle

crystal axle
#

the radius?

remote mural
#

no, the center

crystal axle
#

no

#

i dont know

sinful pasture
remote mural
crystal axle
#

the center looks like thats the radius

#

oh nvm

#

so what is the center

sinful pasture
#

the point in the center of the circle

crystal axle
#

its 12 am here i js want the answer 😭

#

anyone gonna help or what

sinful pasture
#

what do you think the answer is

crystal axle
#

i dont know what the asnwer is

sinful pasture
#

look closely

crystal axle
#

can you just tell me step by step of what to do

sinful pasture
#

the red thing on the left is 2.5 ft

#

what's that red thing called looking at the second picture

crystal axle
#

radius?

sinful pasture
#

yes

#

radius = 2.5 ft

crystal axle
#

ok so whats the next step?

#

now that i know the radius

sinful pasture
#

the diameter is 2*radius if you look at the image

crystal axle
#

so 5?

sinful pasture
#

yes

crystal axle
#

ok so do i do 5*Pi

#

aka 5 x 3.14?

sinful pasture
#

no

#

you are just being asked for the radius and the diameter

crystal axle
#

okay...

#

sorry im just confused

#

and tired

#

how do i find the diameter

sinful pasture
#

you just found it

#

d = 2*r

#

d = 2*(2.5)

#

d = 5

crystal axle
#

2 x 2.5?

sinful pasture
#

yes

crystal axle
#

5

#

oh i just did this

#

so what the answer to the radius

sinful pasture
crystal axle
#

i got the answer

#

Radius: 2.5
Diameter: 5

sinful pasture
#

yes

crystal axle
#

.close

calm coralBOT
#
Channel closed

Closed by @crystal axle

Use .reopen if this was a mistake.

dusky flax
#

diameter is already shown in diagram (1/4 or 0.25 yd)

dusky flax
calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

white mountain
calm coralBOT
white mountain
#

,rotate

potent lotusBOT
white mountain
#

Where do I begin?

sinful pasture
#

you want to maximize the area

#

and the dimensions are x and f(x)

white mountain
#

Yes

sinful pasture
#

Ok so find a maximum for A = xf(x)

white mountain
#

I say x*y
Letting y be e^(-x^2)

#

Is that the right path

sinful pasture
#

yes

#

its more like an optimization problem

white mountain
#

Now what

#

Take derivative?

sinful pasture
#

you want a maximum for the Area, so yes

white mountain
#

e^(-x^2)+xe^(-x^2)*-2x = 0

#

How do I find x?

sinful pasture
#

$e^{(-x^2)}+xe^{(-x^2)}(-2x)=0$

#

ok let me type it correctl woops

potent lotusBOT
sinful pasture
#

you can factorize e^(-x^2)

#

e^a is never 0 so you can already get rid of that term

white mountain
#

(1-2x^2)(e^-x^2)

sinful pasture
#

yes

#

so (1-2x^2)=0 or (e^-x^2)=0

white mountain
#

And only 1 of those could be 0

sinful pasture
#

ab = 0 is the same as a = 0 or b = 0

#

set both equal to 0 maybe to avoid skiping step

#

(for example (x-3)(x-2)=0 is the same as x=3 or x=2)

calm coralBOT
#

@white mountain Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

abstract snow
#

Ask a question

#

this is Arithmetic Progression

#

no wait

#

I read it as A_1 mb

calm coralBOT
#
Channel closed

Closed by @molten dagger

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

astral mural
#

Hello

calm coralBOT
astral mural
#

What does root mean?

#

Why are we using 1/n?

civic dirge
#

3rd root. ³√

astral mural
#

Why not use this equation?

civic dirge
#

Like, the third root of 8 is 2.

astral mural
civic dirge
#

That equation is being used

astral mural
#

Ahhh I see

#

Tysm

#

.close

calm coralBOT
#
Channel closed

Closed by @astral mural

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

atomic heron
#

I want to make a graph

calm coralBOT
atomic heron
#

where basically the mens 100meter world records

#

at on the y axis

#

and the date they were made on is on the x axis

#

but the thing i wanna do is

#

I have a theoretical limit of 8.97

#

so I want an asymptote

#

at 8.97

#

and I want the equation so that I can like predict future world records and when the theoretical limit will be reached

graceful dust
#

hmm it will be hard to fit something “useful” here

atomic heron
#

wdum

graceful dust
#

before anything i would want to see what the points look like, with race time plotted against date

atomic heron
#

this is what it looks like for swimming

#

I want something similar for running, but an asymptote

graceful dust
#

yea i get what you’re asking for

graceful dust
#

i dunno, desmos or something if you just wanna see it, but eventually you’re probably going to need to put the data into some coding language with curve fitting support

atomic heron
#

is it doable on geogebra

graceful dust
#

or maybe wolframalpha will do it but you might want more customization than it offers

#

for seeing the points sure

atomic heron
#

does geogebra have the ability to create the function

graceful dust
#

is what not possible?

atomic heron
#

doing the plotting

#

and the software automatically just giving me a best fit line equation

graceful dust
#

well no software would use the plot, it would use the numerical datapoints

#

you need to be able to specify the conditions you want on the curve though

atomic heron
#

hmm

graceful dust
#

like as an example you might ask it to find the “best” fit among curves of the form y = ae^(-bx) + 8.97

#

so a and b are something the software would compute

#

or you can ask it for some other type of curve with an asymptote, not necessarily an exponential function like that

atomic heron
#

got it

#

makes sense

#

thats yeah

#

ok

#

makes sense

graceful dust
#

you can also try just plotting the points in desmos and playing around with a and b until you find ones that look ok if you want a lower effort “solution” lol

atomic heron
#

lmao

#

its ok

#

need it to be accurate

#

ill try this

#

thanks

#

.close

calm coralBOT
#
Channel closed

Closed by @atomic heron

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

grand shoal
#

find all the value for a and b so that u v w are linearly independent.
I tried using ERO but still can't get the value for a and b respectively

marble olive
#

.reopen

#

.open

calm coralBOT
#

@grand shoal Has your question been resolved?

grand shoal
#

.close

calm coralBOT
#
Channel closed

Closed by @grand shoal

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

marsh blade
calm coralBOT
marsh blade
#

something confuses me here

#

why did we do sin theta = y / 15

#

i am confused

calm coralBOT
#

@marsh blade Has your question been resolved?

near cosmos
zinc crater
#

we took sin theta= y/15 since sin theta = opposite side / hypotenuse

near cosmos
#

Also if your wondering why we only took sin theta it is because we need to compare the theta with something that is variable in the problem. Since the height is varying we took sin theta so that theta can be compared to the rate of change of the height.

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

rich ore
#

Im getting 54 for 5d is it correct?

calm coralBOT
rich ore
#

<@&286206848099549185>

proven pelican
#

Tell ur way

#

As we can't just tell if ur ans is correct or not

rich ore
#

So 3 at start

#

Then 4 num left

proven pelican
#

Hmm

rich ore
#

Out of which 3 can make it even

proven pelican
#

As u want to get even

#

Put max even first

rich ore
#

For each of the 3 there will be 3! Different prrmutations

#

3x3!x3

rich ore
calm coralBOT
#

@rich ore Has your question been resolved?

rich ore
#

<@&286206848099549185>

calm coralBOT
#

@rich ore Has your question been resolved?

torpid spade
# rich ore <@&286206848099549185>

I would suggest considering three cases

i) Those who start with a 4
ii) Those who start with a 5
iii) Those who start with a 6

And then you can add up the amount of solutions for each of the particular cases

rich ore
torpid spade
#

No, it will be in fact easier

calm coralBOT
#

@rich ore Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

proud egret
#

Guys, does anyone know how to find the volume of solid of revolution bounded by two functions, if one of the functions is negative on some interval and positive on the other?

proud egret
#

To be more concrete, here's the problem I was trying to solve:

#

But I'm worried this solution may over or under count the actual volume

#

Maybe computing it as
$$
\pi \int_a^b \left| f^2(x)-g^2(x) \right| , dx
$$

will fix the issue?

potent lotusBOT
#

Sweet Tea 🧋

crystal forge
#

so if that part of the shape isnt contributing any volume (basically it would be going over part of the volume traced out by the upper part of the function) then you can just ignore it altogether

proud egret
#

Hmmm. I think I can see that (at least if we were given only the parabola without the line), but I'm not sure if that works when we have 2 functions as well

crystal forge
#

if you wanted to be technically correct you can show that | lower function | <= | upper function | on the given interval

brazen elbow
proud egret
proud egret
crystal forge
#

so you can just consider the volume traced by this region and set your bounds accordingly or do what fungus suggested and subtract the redundant volume, i guess whichever you think would be easier to set up the integral

brazen elbow
#

thats the redundant volume

#

calculate that too

crystal forge
#

for this ^ way (as in picture) you can do the intgral of line - parabola from first interseciton to x = 0 then just integral of the line function between 0 and the 2nd x intercept, then integral of line - parabola on the right

#

like these 3 regions will have different setups

proud egret
#

So this is usually done just by eyeballing it?

#

Like, no 'universal' formula? blobsweat

crystal forge
#

eyeballing what?

proud egret
#

I think
$$
\int_a^b \left|f(x)-g(x)\right| , dx
$$
for computing the area bounded by f and g on [a, b] will always work, for example

potent lotusBOT
#

Sweet Tea 🧋

proud egret
crystal forge
#

well that still applies on the interval [left intersection of the functions, 0] and [2nd zero of the parabola, 2nd intersection of the functions] and on the one in the middle its just area under a single graph which you know the formula is just a basic integral, but yeah you just to consider what is bounding the region i guess that's all

#

you can also do what fung suggested, both setups are pretty easy to work with i would say

proud egret
proud egret
crystal forge
#

erm yeah sorry not area, use the volume equations

#

like pi (upper function^2 - lower function^2) dx isn't it?

crystal forge
#

for the red and green

#

and purple is just pi (line function)^2 dx

proud egret
#

lemme ask a separate (but still related) question then\
Why doesn't the formula
$$
\pi \int_a^b \left|f(x)^2- g(x)^2\right| , dx
$$
work in this case?

potent lotusBOT
#

Sweet Tea 🧋

proud egret
#

ie why do we need to separate

#

(notice the abs value here)

crystal forge
#

well that piece under the x axis like you say will be counted twice

#

since it traces out the same volume as its reflection above the x axis

#

which is already included

#

so what fung suggested is to just do the integral anyway, not caring about it being counted twice

proud egret
proud egret
crystal forge
#

can you show me where you are reading that on wiki

proud egret
#

one moment

crystal forge
proud egret
# proud egret one moment

https://en.wikipedia.org/wiki/Solid_of_revolution
(It's described for revolution around y-axis, but I guess it also works when we revolve around x-axis)

In geometry, a solid of revolution is a solid figure obtained by rotating a plane figure around some straight line (the axis of revolution), which may not intersect the generatrix (except at its boundary). The surface created by this revolution and which bounds the solid is the surface of revolution.
Assuming that the curve does not cross the ax...

crystal forge
#

this is the problem

proud egret
#

Gotcha

crystal forge
#

actually thats maybe about something else

proud egret
#

Also, do you know of a few (like one or two) exercises for this idea (when a function crossess the axis), preferably with answers
Just want to make sure I got it 100%

crystal forge
#

ok that quote was a bit about something else, but yeah this discussion is when the generating curve is not crossing the axis

#

the generatrix i guess is the curve used to generate the volume so like your function basically, in your case one of these generating curves is in fact crossing the axis of rotation

#

so you can see why that generates issues :d

crystal forge
#

@proud egret you could have something like this where if you are rotating these regions over the x axis and considering volume, well you wouldn't have any issues because neither of the regions has a reflection over the x axis so they would both just be contributing their volume as normal, what you have to consider is just if the area you are rotating has a corresponding area reflected over the axis of rotation, thats what you need to consider

remote mural
#

<@&268886789983436800>

calm coralBOT
#

@proud egret Has your question been resolved?

proud egret
calm coralBOT
#

@proud egret Has your question been resolved?

proud egret
#

Ok, so, here's an example:
I'm trying to properly find the V(sol. of rev. of the green shape when rotated around x-axis)
The functions are given by f(x) = x/2 - 5 and g(x) = -1/10•(x-10)^2 + 5

I'm a bit confused how to approach it.
Do I like draw y=|f(x)| and y=|g(x)| first and try to eyeball it from there?

#

the thing I'm a bit confused it that it isn't always that easy to determine what function will have «greater magnitude»

#

In this example, we'll have
$$
|f(x)|\ge |g(x)|, \quad \forall x \in [0, 5]
$$

but then it changes:
$$
|f(x)|\le |g(x)|, \quad \forall x \in [5, 15]
$$

potent lotusBOT
#

Sweet Tea 🧋

proud egret
#

I've drawn the abs values of the functions (red is $|g(x)|$ and blue is $|f(x)|$) \
And it doesn't look that easy to actually find out when we just have to do $\pi \int_a^b h^2$ and when $\pi \int_a^b h^2 - u^2$ (where u is just a function, I've ran out of letters xDD)

potent lotusBOT
#

Sweet Tea 🧋

proud egret
pulsar vigil
#

What do u need help with

proud egret
proud egret
# pulsar vigil What do u need help with

In particular, I'm a bit confused how to apply the disk method
$$
V=\pi \int_a^b f^2-g^2
$$
when either the functions cross the x-axis or when it isn't true that one of them is always (on the interval $[a, b]$) greater than the other

potent lotusBOT
#

Sweet Tea 🧋

calm coralBOT
#

@proud egret Has your question been resolved?

crystal forge
#

@proud egret hm for this one seems like it'd be easiest to just like find the volume overall including the overlapping part and then subtract what is counted twice, i think the picture you drew earlier is helpful

#

like subtract this part here that is the volume generated by these two regions, the red is a bit easier since its a triangular region that will generate a right circular cone which you dont even have to integrate, you can use the volume formula for a cone, then you can find the volume generated by that blue region using the quadratic

#

ping me if you're back / still need help later

proud egret
crystal forge
calm coralBOT
#

@proud egret Has your question been resolved?

proud egret
#

.close

calm coralBOT
#
Channel closed

Closed by @proud egret

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

light patrol
#

Anyone able to help with beginner scripting in python? Or know a place to get help?

brazen elbow
#

ask your question

#

we answer anything lol

light patrol
#

It’s not a question it’s wanting me to write code and idk where to start or what to do. I’ll send pics

hasty coyote
light patrol
#

I’ll check that out!

hasty coyote
#

you're choosing a harsh path bro, but i'm sure you can do it, KEEP UP sadcatthumbsup

light patrol
#

It’s for a college course that’s kicking my ass lol

#

I’m a geology major, I get why they’re having me learn it but I’m drowning out here

hasty coyote
#

wtf

light patrol
#

FR

hasty coyote
#

GEOLOGY !!!, I'm CS student and yet this rubbish is swallowing me

#

you've got it hard bro

#

F

light patrol
#

It’s not even that I don’t think it’s interesting, I just have a small lizard brain that doesn’t understand math lmao

light patrol
hasty coyote
#

that's fine, even though i study cs, 90% of my study is math and electronics, and 10% left is filled with a bit of useless pascal programs

#

anyways close the channel or the mods gonna get mad devastation

light patrol
#

o7

#

.close

calm coralBOT
#
Channel closed

Closed by @light patrol

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

frozen vault
#

can anyone prove that sinx + cosx*√3 = 0

left canopy
#

,w graph sin(x)+cos(x)*sqrt(3)

left canopy
#

,w graph 0

exotic bane
#

Cause I don't think this equation can be proven for all x

frozen vault
#

I'm actually kind of stuck in the middle of a math and I know the answer to this should be zero?

exotic bane
#

Can I see your work?

frozen vault
#

yea hold up

#

This is the math actually which should be equal to -3/4*sin3x

#

I've already got the answer but there's this part left so i thought it should be equal to zero

calm coralBOT
#

@frozen vault Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

remote mural
calm coralBOT
remote mural
#

I'm asked to show condition work/state conditions met or not met etc.

#

bit confused, I know that the conditons are

#

f(a) exists
limf(x) exists
f(a)=limf(x)

#

how do I find the value at which it is continution/not continuous

#

for a it is quite obvious being 3

#

but how would I prove the 2nd condition

#

f(3) DNE fine

#

wait lmme try smth

#

.close

calm coralBOT
#
Channel closed

Closed by @old nexus

Use .reopen if this was a mistake.

remote mural
# remote mural

When our bottom is equal to zero, the function is not continuous or discontinuous

#

It becomes a vertical asymptote

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

calm coralBOT
#

@full mirage Has your question been resolved?

calm coralBOT
#

@full mirage Has your question been resolved?

calm coralBOT
#
Channel closed

Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

remote mural
calm coralBOT
remote mural
#

I'm noticing the transition points -2 and 0

#

so what I tried was

#

$2=\lim_{x\rightarrow -2}(ax^2+b)$

potent lotusBOT
#

Remlis

remote mural
#

2 because -(-2)=2

#

from the first eq.

cloud nexus
#

Yep

remote mural
#

$2=4a+b$

potent lotusBOT
#

Remlis

cloud nexus
#

And we also need b=6

remote mural
#

this I don't understand

#

why

cloud nexus
#

To satisfy ax^2+b=6 at x=0

#

The quadratic term goes to 0

#

So we are left with b=6

remote mural
#

6=ax^2+b when x=0

#

b=6

cloud nexus
#

Yes

remote mural
#

okay i think I get it

#

that's it?

cloud nexus
#

Basically we want all the boundary connections to be smooth

#

Thats the goal of these types of problems

cloud nexus
remote mural
#

mm

#

$2=4a+6$

potent lotusBOT
#

Remlis

remote mural
#

$-4=4a$

potent lotusBOT
#

Remlis

remote mural
#

$a=-1$

potent lotusBOT
#

Remlis

cloud nexus
#

Yes

remote mural
#

perfect

#

thank you very much

calm coralBOT
#

@remote mural Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

nimble hill
#

@vivid surge

calm coralBOT
nimble hill
#

They closed that channel

vivid surge
#

oh

nimble hill
#

Is this right ?

vivid surge
#

yeah it is

nimble hill
#

The formal is 0, 1

vivid surge
#

it's wrong ;-;

nimble hill
#

I solved like one hour ago 😢

vivid surge
nimble hill
#

Thanks

vivid surge
#

i think the answers given might be a typo

nimble hill
#

Yeah maybe thank you 😊

vivid surge
nimble hill
#

. Close

#

. close

#

IDK how close the channel

lofty nacelle
#

no space between . and close

#

like .close

raw dirge
#

!done

calm coralBOT
#

If you are done with this channel, please mark your problem as solved by typing .close

raw dirge
#

copy paste it

drifting seal
#

.close

calm coralBOT
#
Channel closed

Closed by @drifting seal

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

stable raven
calm coralBOT
stable raven
#

how do i do a

runic rune
#

if f'(x) is in the positive area what does that tell us

stable raven
#

ohh that its increasing?

runic rune
#

yep

stable raven
#

is it concave down because as x --> infinity the values reach 0?

runic rune
#

it is concave down

stable raven
#

but why

runic rune
#

f'(x) is decreasing.

#

if f'(x) was increasing it would be concave up

stable raven
#

ohh okay thank you

#

ohh okay thank you

#

.close

calm coralBOT
#
Channel closed

Closed by @stable raven

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

mighty dagger
calm coralBOT
mighty dagger
#

can i use here l'hopital ?

#

and a>0

pseudo moss
#

no

unkempt drift
#

No, you have a -infinity/0 form

mighty dagger
#

ye ok just asking cuz the teacher used l'hopital to solve this

#

tysm

unkempt drift
#

Npnp

mighty dagger
#

.close

calm coralBOT
#
Channel closed

Closed by @mighty dagger

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

pale panther
calm coralBOT
pale panther
#

I don't understand how they got the domain and range of the bottom one

calm coralBOT
#

@pale panther Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

mighty dagger
calm coralBOT
mighty dagger
#

how did he go from first step to 2nd

#

like ik how he removed the 2 down there by taking out 1/2

#

but how did he move the e^x up and made these stuff

mystic obsidian
modern peak
#

basic rules of exponents?

lucid torrent
#
  1. when a constant is a coefficient of all the variables you can factor it
  2. dividing 1/e^x is same as multiplying the reciprocal
mighty dagger
#

oh wait a min

#

its (all the thing up)/2/e^x

#

so i can move the e^x up

modern peak
#

$\int \frac {e^{1.5x + 3.5} + e^{2x}}{\frac {2}{e^x}} \text { d}x= $0.5\int e^x \cdot (e^{1.5x + 3.5} + e^{2x}) \text { d}x$

#

$\int_{ }^{ }\frac{\sqrt{e^{3x+7}}+\left(e^{x}\right)^{2}}{\frac{2}{e^{x}}}dx=0.5\int_{ }^{ }e^{x}\left(e^{1.5x+3.5}+e^{2x}\right)$

potent lotusBOT
mighty dagger
#

ohhhhh

#

damn ok gotcha

#

ok tysm

#

appreciate it

#

.close

calm coralBOT
#
Channel closed

Closed by @mighty dagger

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

molten moat
#

Hello

calm coralBOT
molten moat
#

My answer is SDZBGDQ

#

And there is no such option

#

From the first example of student

#

I thought it just changed the letter and put the letter preceeding it

#

S is replaced by R because it is before it and T by S and so on

#

And hence C should have been replaced by B

graceful dust
hot creek
bronze adder
#

this question is...

molten moat
#

I only went for 3 letters and stopped

#

Thank you

#

then the fourth answer is correct

#

Thank you

#

.close

calm coralBOT
#
Channel closed

Closed by @molten moat

Use .reopen if this was a mistake.

molten moat
#

I mean 3rd

#

.close

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

shy light
calm coralBOT
shy light
#

What should I do after this

#

Stuck with it from yesterday

#

I've got 4 equations but it turns out to be a loop

marble escarp
#

Question? 🙂

shy light
#

find the angle CFD

#

Here it is

#

Here is something I've tried

remote mural
#

Does this work

shy light
#

I've already tried it

#

And the equations come out to be a loop

remote mural
#

Ohhh

shy light
#

<@&286206848099549185>

dull wagon
#

why does noone read what i say

marble escarp
#

Did you write anything above?

shy light
marble escarp
#

About?

shy light
#

I've made some constructions

#

And I've read adventitious triangle

marble escarp
#

Oh the instructions

#

Didn't 'bot' say it though?

shy light
#

what are you saying I don't get anything

marble escarp
shy light
#

It was a problem from yesterday

marble escarp
#

Oh, my bad

shy light
#

And he suggested us to read adventitious triangle

#

but that problem and this problem is a bit different

#

and I'm stuck in the midway

calm coralBOT
#

@shy light Has your question been resolved?

calm coralBOT
#

@shy light Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

remote mural
#

Why they did (A-7I) and not

calm coralBOT
remote mural
#

$\frac{Ax}{7}$

potent lotusBOT
#

Eigenvalues

left sorrel
#

to show that there's nontrivial solutions, you have to show that Ax = 0 for nontrivial x's

#

so $Ax = \lambda x \rightarrow (A - \lambda \mbb{I}) x = 0$

potent lotusBOT
#

nyxie9151

left sorrel
#

this "form" does exactly that

#

you show that there's a nontrivial x that solves (A - lambda* I)x = 0

#

which is equivalent to showing that the determinant (A - lambda*I) = 0 or the columns/rows are linearly dependent

calm coralBOT
#

@remote mural Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

potent lotusBOT
#

mathematician8256

#

mathematician8256

#

mathematician8256

cloud nexus
#

why are you deleting messages

#

??

#

the fuck?

calm coralBOT
#
Channel closed

Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.

brittle siren
#

wth

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

midnight thistle
#

could anyone explain this terrible markscheme to me please 😭

calm coralBOT
#

@midnight thistle Has your question been resolved?

alpine gust
#

y = k - x = 6 - (x-3)^2

#

after some simplification and rearranging u will get a quadratic equation that must have two roots

#

cuz he says that it intersect at two different points

midnight thistle
alpine gust
#

also the roots will have the variable k in it

alpine gust
midnight thistle
alpine gust
#

6 -( x^2 - 6x +9)

midnight thistle
alpine gust
midnight thistle
#

i see so then that simplifies to x^2 -7x + (3+k) but then how do i find the roots of this

alpine gust
#

in order to have two roots, the value of b^2 - 4ac should be greater then zero

midnight thistle
alpine gust
#

thats what im trying to figure 😂

#

one way is to say k = x + y

#

= 3 + 2sin(t) + 4 + 2cos(2t)

midnight thistle
alpine gust
midnight thistle
calm coralBOT
#

@midnight thistle Has your question been resolved?

calm coralBOT
#

@midnight thistle Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

winter herald
calm coralBOT
winter herald
#

isnt L1 = 2???

pure kayak
#

what?

winter herald
#

and arent Lucas numbers defined by Ln + Ln+1 = Ln+2

pure kayak
#

L1's value is defined as part of the equation

winter herald
inland vortex
#

the 0th lucas number is 2

winter herald
#

but okay lets just assume it starts from 0

inland vortex
#

in the question youve given, yes, which is why we have L_1 = 1

#

The Lucas sequence is an integer sequence named after the mathematician François Édouard Anatole Lucas (1842–1891), who studied both that sequence and the closely related Fibonacci sequence. Individual numbers in the Lucas sequence are known as Lucas numbers. Lucas numbers and Fibonacci numbers form complementary instances of Lucas sequences.
T...

#

on wikipedia we see n = 0 is defined as 2

winter herald
#

why are the fibbonacci numbers in the DEFINITION of lucas numbers

inland vortex
#

but since theyre equivalent, they chose to state the fibonacci version as "the definition"

winter herald
inland vortex
#

theyre only asking you to prove one direction

winter herald
#

but i wont be satisfied then '^'

#

lol

#

ok

inland vortex
#

i think the proof will probably give u both directions for free

#

since ur showing that the two sequences coincide after all

winter herald
#

okey

#

let me try for some time

winter herald
inland vortex
#

yea sure

winter herald
#

okay

#

i proved one direction i guess

#

and the L1 = 1 is probably a typo

winter herald
#

OK

#

that is if L1 = 2

#

nah

#

the book is a bit badly written i guess

#

no problem

#

got it

#

kay thanks @inland vortex

#

.close

calm coralBOT
#
Channel closed

Closed by @winter herald

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

dusky crescent
#

Can anyone help with this question?

calm coralBOT
pallid halo
#

compare the real and imaginary parts of the LHS and the RHS

ocean cypress
#

z^3/4 = i
z^3 = i^4 = 1

#

take the cube root. you will get 3 solutions

#

some of them are extraneous

#

you will have to plug them back in

dusky crescent
#

THis is the similar example we had in class but with a real number

#

I think I have to do a similar process to this

#

but how would I know the argument

pallid halo
#

you can solve that last equation in the usual way

dusky crescent
#

I think I am missing something

pallid halo
#

look here

#

the magnitude of the LHS is 1, so the magnitude of the RHS is 1

#

thus r^(3/4) is 1

#

so r is 1

dusky crescent
pallid halo
#

sin(3/4 theta) = 1

#

so 3/4 theta = pi/2 + 2pi n
where n can be any integer

#

now solve for the values of theta in say [0,2pi) that satisfy this

dusky crescent
pallid halo
#

take the imaginary part of this equation:

#

what do you get?

dusky crescent
#

The part before the sin?

#

or the LHS

pallid halo
#

the whole equation

#

what's the imaginary part of the left hand side?

dusky crescent
#

1

#

but wouldn't that mean 1(sin(3/4theta)

#

How do you arrive that 3/4 theta is pi/2 + 2pi n ?

pallid halo
#

1 = sin(3/4 theta), right?

#

sine of what angles gives you 1?

dusky crescent
#

I think I am forgetting some rule or something

pallid halo
#

can you clarify?
are you ok with the equation 1 = sin(3/4 theta) or are you confused about where it came from?

dusky crescent
#

Yeah I am confused about where it came from

#

Like why multiplying the imaginary part by the angle gives 1

pallid halo
#

suppose i have an equation of the form:
a + bi = c + di

#

where a,b,c,d are all real

#

that mean:
a = c
and
b = d

#

now apply that to this equation

#

the left hand side can be written as 0 + 1i

#

and the right hand side can be written as $$r^{3/4}\cos(3\theta/4) + i r^{3/4}\sin(3\theta/4)$$

potent lotusBOT
pallid halo
#

so:
a = 0, b = 1

#

c = r^(3/4)cos(3 theta/4)
d = r^(3/4)sin(3 theta/4)

#

b = d gives you...

dusky crescent
#

1

#

ohh that makes so much more sense now!!

#

Thank you : )

#

Does that mean I can just write the equation as r^3/4cos(3/4 theta) + 1

#

@pallid halo

pallid halo
#

if you want to use the cosine term, that's the real part of the RHS

#

so you'd want to equate that with the real part of the LHS

#

i.e.

#

you would be doing
a = c

#

in this case
a = 0, and c = r^(3/4)cos(3 theta/4)

#

so your equation would be
0 = r^(3/4)cos(3 theta/4)

#

which will give you the same solutions

dusky crescent
#

@pallid halo

#

Is there any way I can do that for this question as well?

pallid halo
#

she did get rid of it

#

that's what is happening when going from the top equation here to the two bottom equations:

dusky crescent
#

where did she get the 2n+1 from

#

@pallid halo

pallid halo
#

she wants r^15 = 2
and cos(15 theta) = -1

#

cosine is negative at pi

#

plus any multiple of 2pi

#

in other words, cosine is multiple when the angle is pi + 2pi n for any integer n

#

which you can rewrite as pi(2n+1)

dusky crescent
#

okay so for this question how would I figure that piece out ? @pallid halo

#

like with 3/4 theta

calm coralBOT
#

@dusky crescent Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

glacial raptor
#

Need help on probability and statistics. Distribution of sample mean

cloud nexus
#

which question

glacial raptor
hasty fiber
#

a should be obvious, the question tells you the parameters explicitly

glacial raptor
#

overthinked it

hasty fiber
#

b should also be clear, you just need to take into account that your sample size is 14

glacial raptor
#

I'm thinking to hard on this...

hasty fiber
#

You have to find the mean and std dev yes

glacial raptor
#

X x-bar = 64, STD X-bar= 5.34

hasty fiber
#

I don't like X=64

glacial raptor
hasty fiber
#

It is

#

But X is a random variable, not the mean

glacial raptor
hasty fiber
#

Anyway, carry on

glacial raptor
hasty fiber
#

64 looks fine to me

glacial raptor
calm coralBOT
#

@glacial raptor Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

trim ermine
#

when i find the oblique asymptote, for example for the equation

$\frac{3x^2-2x-17}{x-3}$

i'd get $3x+7$

if a question asked "determine whether the curve approaches the OA from above or below"

with limit notation, how would I show the sides the equation approached the OA from

$\lim_{x->\infty}f(x) = (3x+7)^+$

would that be valid?

potent lotusBOT
#

notnick

brisk pelican
#

Now I don’t think so

#

At least I’ve never seen that notation or heard of that defined

#

What you can do is show that the equation can be written as 3x+7 + (something over x-3)

#

Maybe 4/(x-3)? Not sure

#

But anyway that goes to 0 when x is big

#

But this shows that the equation is always a bit above the asymptote

calm coralBOT
#

@trim ermine Has your question been resolved?

trim ermine
#

but yeah im not sure either

#

my teacher is a bit strange

#

as well as this textbook

#

like i could easily write "f(x) approaches the OA from above as x -> infty"

#

but that is a bit long

brisk pelican
#

The extra factor goes to 0

trim ermine
#

extra factor?

#

no im talking about oblique asymptote

brisk pelican
#

Dawg 😭

trim ermine
#

the OA is 3x+7

brisk pelican
#

You gon make me use latex on mobile

#

Ok gimme a second

trim ermine
#

um 😭

brisk pelican
#

$\frac{3x^2-2x-17}{x-3} = \frac{3x^2-2x-21}{x-3} + \frac{4}{x-3} = 3x+7 + \frac{4}{x-3}$

potent lotusBOT
brisk pelican
#

Wow I was sure that wasn’t gonna a compile

#

Let’s get it

trim ermine
#

ahhh

#

OH

#

um

#

im still not sure what a proper answer for 8a would be tho

brisk pelican
#

Well you just have to ask yourself if 4/(x-3) is positive or negative for big x

#

Obviously it’s positive

#

So as x goes to infinity, the function will be just barely greater than 3x+7

#

But in the limit the difference is negligible and it goes to 0

#

Make sense?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

snow bough
calm coralBOT
snow bough
#

Why is this false? I can't find anything wrong with it except for the right integral missing a dx

calm coralBOT
#

@snow bough Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

eager forge
calm coralBOT
#

Please don't occupy multiple help channels.

eager forge
#

How do i do ths?

eager forge
calm coralBOT
#

@eager forge Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

calm coralBOT
warm warren
#

Well if 14y = 13k then surely y is a multiple of 13

ocean cypress
#

gcd(13,14) = 1

#

in fact:

#

gcd(n, n+1) = 1

#

always!

#

25 - x is an integer

#

let that integer = k

#

14y = 13k

#

then divide both sides by 13

#

14y/13 = k

#

the right side is an integer because k is an integer

#

so the left side must also be an integer

#

then invoke euclid's lemma

#

13 is a prime, and if 13 | 14y, then either 13 | 14 or 13 | y

#

13 does not divide 14 because of what i said above about n being coprime to n+1

#

so 13 must divide y

#

25 - x is an integer

#

if a prime p divides the product ab, then p divides a or p divides b

#

here's an example:
3 divides 12 * 2, so either 3 divides 12 or 3 divides 2

#

is that not given?

warm warren
#

So a natural number

#

If it’s true for integers then its then it’s true for counting numbers because counting numbers are a subset of integers

calm coralBOT
#
Channel closed

Closed by @ruby bay

Use .reopen if this was a mistake.

calm coralBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

white mountain
#

why does lhopital only apply to indeterminate cases

runic rune
#

if the limit is determinate, then you have your solution

white mountain
#

But lhopital does not work for determinant form

#

Why

runic rune
#

.. to prolly simply put it, its because its not needed. its better to just direct substitution at that point

white mountain
#

But why can it not be used

#

What makes it not work

#

Because it doesn’t work for determinant form

#

It’s not a matter of easier or harder

pale blade
#

If you're interested in understanding why L'H doesn't work on conventional limits, start by understanding why L'H works for indeterminate ones, from a physical perspective

white mountain
#

And why is that

pale blade
#

Well if you don't know how the limits of a function's derivatives relate in a compartive (inf/inf or 0/0) case, its tough to figure out why it (might) fail when the limit is determinate.

#

What happens when you apply l'h to a limit that has already been solved by it? You get the wrong answer

white mountain
#

Okay, but why

#

if I were to lhopital lim x->2 (2x+4)/x I would not get an undefined answer, I would get the wrong answer

#

What is so special about f(x) and g(x) being 0 that makes it work

pale blade
#

If you decompose a regular l'h limit into its two consitituent functions, the visual intuition of l'h is that even though both f(x) values are zero, they have different rates of change. Since you have no initial "displacement", these rates of change dictate the nature of these two functions (or their ratio) in the neighbourhood of x=a

#

To illustrate:

#

Now, what if f(x) and g(x) don't match?

white mountain
#

I get the f(x) and g(x) being seperate functions but how does the df and dg give you lhopital

pale blade
#

Because we want to get the limit of f/g

#

since f=g=0 at the point where they intersect, we use their derivatives to model what will happen right afterwards

#

aka their derivatives respectively, df and dg

#

get their quotient

#

and that lh for you

#

,rotate ccw

potent lotusBOT
pale blade
#

You end up with something like this if f is not equal to g at the point of interest

#

now the ratio of "dg" and "df" have no meaning, since the increment from f=0 and g=0 is nonzero, meaning f hits zero first, before g

#

to correctly apply the same process, we would need the two "beams" to start from the same place, where the two functions are equal to zero

#

All of this requires a comparison to be made from the same starting point

#

and beyond that, from the same starting point where f=g=0, since starting at any other value (f=g=a) while trivial (lim = 1 duh), would cause l'h to fail, due to the added "increment" that differentiates the intended "limit of derivatives" to be used for l'h and simple limit of derivatives one would try to use for it.

#

All of this is a bit hand wavy (and way beyond the level of calculus 1). The formal proof uses the mean value theorem IIRC

white mountain
#

Why can’t they both just equal 1

#

And work from there

pale blade
#

Try to draw it out. You'll have a sort of "increment" that screws up the dg/df ratio

white mountain
#

Wdym

pale blade
white mountain
#

I’m lost

white mountain
pale blade
#

Try to think about it this way

#

We can get the relative change of f and g when they both equal to 1

#

But that change is infinitesimal

#

Compared to the big green box (from y = 0 to 1), whatever difference in their rates of change there is is completely irrelevant

ADDENDUM: This ratio is thus only relevant when there is no big green box (ie. when f=g=0).

#

It’s ultimately adding an infinitesimal to a number, 1+0.0…2 = 1

#

Sure, red grows faster than blue, but 1.0000..2/1.0000..1=1 still

#

In all honesty though, I wouldn’t overthink it unless it’s out of personal interest. The “formal” way of expressing and communicating this is beyond Calculus 1. You’ll get more exposure to it if you end up taking Analysis

calm coralBOT
#

@white mountain Has your question been resolved?

calm coralBOT
#
Channel closed

Closed due to timeout

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

tall moon
#

assume there is an isoceles triangle ABC where AB=AC, point E is the midpoint of line AC, and point K is the intersection point of the line that bisects CAB and the circle that touches point A, B, and E, prove that the diameter of the circumcirle is $\frac{4}{3}$ times AK

potent lotusBOT
#

Skill_Issue

tall moon
#

it would look something like this

#

i have no idea where to start this

calm coralBOT
#

@tall moon Has your question been resolved?

dusky flax
#

hm

calm coralBOT
#

@tall moon Has your question been resolved?

calm coralBOT
#

@tall moon Has your question been resolved?

calm coralBOT
#

@tall moon Has your question been resolved?

tall moon
#

<@&286206848099549185>

calm coralBOT
#

@tall moon Has your question been resolved?

left canopy
#

Okay, I suppose I have a somewhat computational proof to get some Intuition

#

You can compute the circumradius of AEB. Let O be the center of this circle. From there, you can compute the angle of the arc AOE and EOK which should give you the angle AOK. You can use this angle and the circumradius to compute AK. Then compare that value to the circumradius of ABC.

calm coralBOT
#

@tall moon Has your question been resolved?

tall moon
left canopy
#

It's double the angle EAK and, AOE you can find using the length of AE

tall moon
#

if so how?

#

oh wait nvm

#

do i use trig for AOE?

tall moon
#

arc EK=$\pi r(\frac{EAK}{90})$
arc AE=$\pi r(\frac{sin^{-1}(\frac{AE}{2r})}{90})$

potent lotusBOT
#

Skill_Issue

tall moon
#

um

#

EOK=4EAK $\quad$
AOE=$4sin^{-1}(\frac{AE}{2r})$

potent lotusBOT
#

Skill_Issue

tall moon
#

wait

#

arc AK=$\pi r(\frac{EAK+sin^{-1}(\frac{AE}{2r})}{90})$

potent lotusBOT
#

Skill_Issue

tall moon
#

AOK=$4EAK+4sin^{-1}\frac{AE}{2r}$

potent lotusBOT
#

Skill_Issue

tall moon
#

AK=$2r sin(2EAK+2sin^{-1}\frac{AE}{2r})$

potent lotusBOT
#

Skill_Issue

tall moon
#

D: this is absurd why would the olympiad have this question