#help-4

1 messages · Page 18 of 1

fleet junco
#

also i just realied this simplifies to P(min >= x) = 1/x

#

so thats really cealn

#

so the answer is

#

1 + 1/2 + 1/3 + 1/4 + 1/5

#

damn thats a cool problem

night patio
fleet junco
#

im pretty sure

#

i dont see anythting wrong with the logic

night patio
#

this sums up to 2.28333333333

#

and what i was told that the answer was 2.45

night patio
#

I might be wrong tho

night patio
fleet junco
#

says

#

its including

#

the 5 roll

#

whihc means the minimum cannot go above 5

#

so ur 2.45 might be

#

not including

#

the 5 roll

night patio
#

i really don't know. Can you explain me your solution

fleet junco
#

ok

#

so

night patio
#

I have not studied this expected value stuff

fleet junco
#

do you see why this would be true?

night patio
#

let me think

#

i think i almost got it

#

just 1 min sorry

fleet junco
night patio
#

yupp just 1 min

#

i think i got it

#

(i took the starting value n = 1 here)

#

but yes i get what you are saying

night patio
# night patio

now if we pair up terms on the right, we'll get this expression

fleet junco
night patio
#

totally makes sense

fleet junco
#

liek each >= is just hte sum of the equalities

night patio
#

yes and each term will have n copies of itself

fleet junco
#

and the counts of easch

#

amke it exaclyt x

#

yep

#

ok

night patio
#

got it

fleet junco
#

so knowing

#

that we only

#

ahve to find a way

#

to calcualte

#

P(min >= x)

#

and the probelm is solved

#

so for min >= x

#

u have to have some number of rollls

#

= x

#

and a final roll of 5

#

so for a length n sequence

#

u have n-1 rolls >= x and a final roll equal to 5

#

also those n-1 rolls do not equal 5

#

so that leaves u with 6-x possible numbers to roll

night patio
fleet junco
#

yes

#

and the chance u roll something >= x and not euqal to 5 is just (6-x) / 6

#

so u do that n-1 times with a final 1/6 chance to roll a five

fleet junco
#

gives you the probabliltiy for any length n sequence

night patio
#

yupp

fleet junco
#

u add taht up, giving u this forumula

night patio
#

okay makes sense

fleet junco
#

and qed

night patio
#

we add that up

fleet junco
#

then u geometric series to find its just 1/x

night patio
#

yes i will simplify that part

#

and i totally got

#

i got how we found this

#

but what i dont get is

#

P(min >=5) + P(min >= 4) + P(min >= 3) + P(min >= 2) + P(min >= 1)

#

this

night patio
#

how does this give us the expected minimum

#

can you explain it a bit intuitively if you have time?

fleet junco
#

here i will write it more explicityl

night patio
#

like i totally get this part

#

this is simple

#

but why are we adding these in the first place? how do these give us the expected value?

fleet junco
#

P(min >= 1) = P(min = 1) + P(min = 2) + ... + P(min = 5)
P(min >= 2) = P(min = 2) + ... + P(min = 5)
P(min >= 3) = P(min = 3) + ... + P(min = 5)
P(min >= 4) = P(min = 4) + P(min = 5)
P(min >= 5) = P(min = 5)

#

u get that?

unreal warren
#

gulp

night patio
unreal warren
fleet junco
#

up

night patio
#

thats how i was able to prove that thing

fleet junco
#

u get our sum

#

=

#

1 * P(min=1) + 2*P(min=2) + ... + 5*P(min=5)

#

whihc is exactly

#

the definition

#

of expected value

night patio
#

okay thats what i didn't know

fleet junco
#

sry i shouldve made it celarrer

#

that this was the definition of epxected value

night patio
#

and why is it defined that way?

fleet junco
#

well its like an average

#

its

#

value * probablity of getting that value

night patio
#

like we are weighing stuff up

#

and adding it

fleet junco
#

so its bsaiclay an average

#

yeah a weighted avberage

#

cuz think of it like this

#

lets say u ahve a coin flip with 80% heads

#

then your expected number of heads

#

is

#

0 * .2 + 1 * .8

#

because tails = 0 heads

#

and heads = 1 heads

#

ig thats not a very good example

#

but its just a weighted average

night patio
# fleet junco 0 * .2 + 1 * .8

okay its like we want to know how many heads do i get (given that i know how many percent i can get or like the probability of a head)

now since i want to know the number of heads, i put tails = 0 and multiply probability of getting 0 tails with 0 and add that to probability of getting heads * 1

#

something like that

#

did i just write a lot of nonsense

fleet junco
#

no ur right

#

but heres a better example

#

liek lets say you pull a ball from a box

#

50/50 chance theres two balls

#

but one ball is 10kg and the otehr is 1kg

#

then whats the expected weight of the ball

#

would be

#

10 * .5 + 1*.5 = 5.5

night patio
#

10* 1/2 + 1 * 1/2

fleet junco
#

yeha

night patio
#

totally makes sense

#

so the general formula is weight * P(weight)

fleet junco
#

yep exaclty

#

and also the reason its litearlly a weightred average is because

#

sum of probabilities = 1

#

cuz normally in a weighted avg u have like

(ax + by + cz) / (a + b + c)

#

is the weighted average of x,y,z with weights a,b,c

#

but in probablilty, the probablilites act as weights, and since they sum to one the denominator is 1, which is why there is no denomintaor

night patio
#

not the probability

#

so is it the probability that acts as the weight?

#

i guess that makes sense

#

like if we increase the number of 10kg balls to 2

#

then 10 * 2/3 + 1 * 1/3

#

the probabilities change but the objects remain the same (i.e. the 10kg and 1kg balls)

fleet junco
#

so value would be a better word

fleet junco
night patio
#

hmm makes sense

#

and so we generalised this definition of expected value just like that?

fleet junco
#

yeah

night patio
#

w * P(w)

#

are there any other definitions too?

fleet junco
#

i dont think so

night patio
fleet junco
#

like EV is defined to be the weighted average with respect to probabilities

#

nothing more nothing less

night patio
#

but I still can't wrap my head around the die problem

fleet junco
#

its just what it is

fleet junco
#

its hte same idea

#

like take expected value of just a single dice roll

#

each value 1,2,3,4,5,6 has probabliltiy 1/6

#

so its just liek drawing weighted balls

#

aucaltly the idea of EV also

#

is that

#

if u repeat

#

the trial

#

an infinite number of times

#

then EV is the average value you will get

#

so in your original problem

#

there maybe liek a 20% chance u get a minimum of 3

#

so if u reapeat ur problem an infinite number of times and note the minimum each time

#

and average them up normally (not weighted) then u will get teh EV

night patio
#

got it

#

so a distribution

#

right

#

of minimums

fleet junco
#

yes, in that given probelm

night patio
#

and the value 2.2833 lies in the middle

#

its the average for infinite number of trials

#

lets assume a very simple model for this problem

fleet junco
#

yes

night patio
#

since they want an average or expected value

fleet junco
#

so in the 20% of 3 case, 20% of all ur trials

#

will return a 3

#

and so it makes sense to assign it a weight of .2

night patio
#

i could have just done (1 + 2 + 3 + 4 + 5)/6

#

but that won't be right

night patio
fleet junco
#

yes

night patio
#

and those weights are the probabilities for getting that respective number

fleet junco
#

yes

#

because probalbitly is the frequency/proportion

#

of ur infinite

#

trials

#

that will give that value

#

also to clarify, in this case, a single tirla is one sequence of rolling til u get a 5

night patio
#

(1 * P(1) + 2 * P(2) + 3 * P(3) + 4 * P(4) + 5 * P(5) + 6 * 0)/6

fleet junco
#

no

#

not /6

#

becuase u divide by the sum of the weights

#

which is 1 due to how probability works

night patio
#

i need to think more

#

thankyouu ^^

fleet junco
#

yeah just sleep on it

night patio
#

2.45 was wrong

#

wrote this code and ran it for a million trials

vale dockBOT
#

@night patio Has your question been resolved?

tender field
#

@night patio was aa2 able to explain this problem? If not I can try to solve it

#

You can probably get away with a tail sum

#

$$E[X] = \sum_{i = 1}^{5} \mathbb{P}(X \geq i)$$

rocky lotusBOT
#

utop!a

tender field
#

alright :)

night patio
#

the final answer came out to be 1 + 1/2 + 1/3 + 1/4 + 1/5

#

@tender field can you confirm it

tender field
#

yep

#

i got the same answer

#

very beautiful question ❤️

night patio
night patio
vale dockBOT
#

@night patio Has your question been resolved?

#
Channel closed

Closed by @night patio

Use .reopen if this was a mistake.

vale dockBOT
#
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.

static vigil
#

.

quick mica
vale dockBOT
viscid spade
#

Need help to write the integral?

quick mica
#

hold up lemme word this right

#

So for the second question in using chain rule u integrate it right?

viscid spade
#

What is the integral you wrote

quick mica
#

But the answers say it’s 2/9 instead of 9/2

#

I’m just confused how it’s 2/9

viscid spade
quick mica
#

and this is the answers

viscid spade
glass kelp
#

1/3 * 2/3 =2/9

#

It’s 1/3 * (1/(3/2)) =1/3*2/3

desert stone
quick mica
#

I thought we needed to multiply it by 3/2 by 3

desert stone
#

I am confused as why there are two integrals on your scratch paper

desert stone
#

Becasue when you use the curve above subtract the curve below at point of intersection it should give you the correct result, there is no change order of curve

glass kelp
#

[ \int_2^6 (3x-2)^{1/2} \dd x]
Let ${u = 3x-2}$. Then ${\dd u = 3\dd x}$, so ${\dd x = \frac{1}{3}\dd u}$
[ \int_{u=4}^{16} u^{1/2} \left(\frac{1}{3}\dd u\right) = \frac{1}{3}\int_{4}^{16} u^{1/2} \dd u = \frac{1}{3} \left[\frac{u^{3/2}}{3/2}\right]^{16}_{4}]
Simplifying,
[ = \frac{1}{3}\frac{2}{3} \left[ u^{3/2}\right]^{16}4 = \frac{2}{9} [u^{3/2}]{4}^{16}]

desert stone
#

So you set up the integral or you can’t compute?

desert stone
quick mica
desert stone
#

You don’t need a second integral

desert stone
#

Your first integral include the correct and sufficient information

quick mica
#

I think I finally get it

quick mica
rocky lotusBOT
glass kelp
#

There we go

quick mica
#

.close

vale dockBOT
#
Channel closed

Closed by @quick mica

Use .reopen if this was a mistake.

vale dockBOT
#
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.

pallid bronze
#

Yo anyone here ?

vale dockBOT
normal hollow
#

Question plz

pallid bronze
#

are u math expert?

normal hollow
#

No i m not

#

But there r others

jovial edge
#

No... But we will try our best to help

hollow shuttle
#

it really depends on the question

pallid bronze
#

I don't have questions lol 😭

#

Sry

hollow shuttle
#

,

jovial edge
#

Oh...

glass kelp
#

Bruh

normal hollow
#

...

glass kelp
#

!close

desert stone
#

Do you want a question?

pallid bronze
#

But I need ur helps when I will be in class 9th

glass kelp
#

What kind of paradox is this gng💔

normal hollow
#

Future prep

jovial edge
#

Yeah.... We will help you with your problem when u have one

normal hollow
#

Booking a channel

noble anvil
#

.close

vale dockBOT
#
Channel closed

Closed by @noble anvil

Use .reopen if this was a mistake.

noble anvil
#

Come when you have a question

vale dockBOT
#
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.

night peak
#

Hi, i do not understand how to solve this nor this solution? Could someone explain how is the 2nd step of the solution equal to 1, 3rd to 5?

normal hollow
#

U see log7(1) =0

#

Do u agree?

#

7 is the base here btw

night peak
#

ohh

normal hollow
#

Do u understand

night peak
#

yess

#

that made me understand the next step too

normal hollow
#

Yes

night peak
#

the only way to get 1 would be if log2(x) was 5

#

Thanks!

#

.close

vale dockBOT
#
Channel closed

Closed by @night peak

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.

polar jasper
#

Let x,y,z>0. Prove that (x+y)/z^2 + (z+x)/y^2 + (y+z)/y^2 >= 2(1/x+1/y+1/z)

polar jasper
earnest ingot
#

What have you tried?

polar jasper
#

and rearranging inequality

#

this one

polar jasper
slate folio
#

you don't need any of that

#

you add 1/x + 1/y + 1/z to both sides

polar jasper
#

oh

#

It was at the inequality theorems chapter so i thought i should use one of those

slate folio
#

nah I found out you don't need those

#

Only Cauchy-Schwartz/Bunyakovsky is enough

polar jasper
#

ok

slate folio
polar jasper
#

Ive gotten down to

#

(x+y+z)(1/x+1/y+1/z)>= 9

slate folio
#

yep

frozen ledge
#

then AM-HM

polar jasper
#

yeah

frozen ledge
#

divide both sides by 3(1/x + 1/y + 1/z)

polar jasper
#

alright

#

yeah i think i got it

#

i just overcomplicated it lol

#

thanks!

slate folio
#

no problem

polar jasper
#

.close

vale dockBOT
#
Channel closed

Closed by @polar jasper

Use .reopen if this was a mistake.

vale dockBOT
#
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.

vale dockBOT
next vortex
#

have you tried anything? catthink

desert idol
#

nope I have no clue

next vortex
#

what does it mean for f and g to have an intersection point? holothink

#

of course, their graphs intersect at an intersection point, but what does it mean algebraically? happy

desert idol
#

they equal to each other

#

f(x) = g(x)?

next vortex
#

yup!

#

try setting the two functions equal and seeing where you can go holoapple

desert idol
#

I got k>√(2)-3 and k<-√(2)-3

tidal swift
#

i have a feeling you will have to consider the fact that those two graphs can intersect twice, meaning you may need a quadratic if you didn't use that already

vale dockBOT
#

@desert idol Has your question been resolved?

#
Channel closed

Closed by @desert idol

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.

trim belfry
#

Hi can someone help me with this question? Im having trouble dealing with area under the curve for polar coordinates

pure mirage
trim belfry
#

pi/2

#

This is how it looks like on desmos

#

Im confused with the constant and bound for integration

slim summit
#

there are two intersections

trim belfry
#

yea if its in a normal cartesian plane i could integrate it normally but idk how to deal with polar plane. the 4 axis on this plane is 0, pi/2, pi, 3pi/2

slim summit
# trim belfry yea if its in a normal cartesian plane i could integrate it normally but idk how...

Let us prove the formula for the area between two polar curves ( r_1(\theta) ) and ( r_2(\theta) ), where ( r_2(\theta) \geq r_1(\theta) ) on the interval ( \theta \in [a, b] ).

In polar coordinates, the area swept by a curve ( r(\theta) ) from ( \theta = a ) to ( \theta = b ) is given by:
[
A = \frac{1}{2} \int_a^b r(\theta)^2 , d\theta.
]

This comes from approximating the area of a small sector as:
[
dA = \frac{1}{2} r^2 d\theta.
]

Now, the total area enclosed by the outer curve ( r_2(\theta) ) is:
[
A_{\text{outer}} = \frac{1}{2} \int_a^b r_2(\theta)^2 , d\theta,
]
and the area enclosed by the inner curve ( r_1(\theta) ) is:
[
A_{\text{inner}} = \frac{1}{2} \int_a^b r_1(\theta)^2 , d\theta.
]

Therefore, the area between the two curves is:
[
A = A_{\text{outer}} - A_{\text{inner}} = \frac{1}{2} \int_a^b \left[ r_2(\theta)^2 - r_1(\theta)^2 \right] , d\theta.
]

rocky lotusBOT
trim belfry
#

okay thanks for helping

#

.close

vale dockBOT
#
Channel closed

Closed by @trim belfry

Use .reopen if this was a mistake.

vale dockBOT
#
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.

dusk cosmos
#

why solve the negation? something to do with the equal-to? i got the same answer either way

stark wedge
#

no it's rather that |A| < B is somewhat easier to handle than |A| > B

dusk cosmos
#

oh ok yeah i see now, i wrote -3>...>3 in my second step and didn't notice that that makes no sense, it just happened to work out

#

thanks!

#

.close

vale dockBOT
#
Channel closed

Closed by @dusk cosmos

Use .reopen if this was a mistake.

torpid scaffold
#

1+1=3

vale dockBOT
#
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.

glass finch
#

How do I solve this question? I don't know how to factor.

west cloud
#

Has your teacher gone over how to factor yet?

#

He/she should have, if you're getting these types of problems.

#

An alternative is using long division for polynomials, but I doubt you'd know how to do that if you don't know how to factor.

glass finch
#

No, I'm applying for college. I am very rusty. I haven't done math since high school.

west cloud
#

ah

#

then you should definitely learn how to factor

cloud coral
old belfry
#

yeah there are a few ways to do this but focus on factoring

cloud coral
#

But polynomial long division should be a standard skill

glass finch
cloud coral
#

I see this and im like... ||just use quadratic formula||

glass finch
#

I skipped math class like every day in high school too on top of that... 😭 💀

#

I regret it

west cloud
west cloud
#

but OP should still learn to factor and do polynomial division

glass finch
#

teach me

west cloud
#

you can use khan academy

old belfry
#

khan academy is good

glass finch
#

ok

#

how would you solve that problem though?

old belfry
#

in this case its quite easy to factorise but if it isnt, use quadratic formula

#

for this particular case id immediately factorise

glass finch
#

so how do you factor?

west cloud
cloud coral
#

For this case ill immediately use quadratic formula. If it doesnt immediately pattern match something I can factor, i just take out the foolproof method

noble anvil
west cloud
noble anvil
old belfry
#

yeah

glass finch
#

3x^2 x -18? = -54....

27 x -2 = 54 the number we just got and also 27 + -2 = 25

#

3x^2 + 27x - 2x -18

vale dockBOT
#

@glass finch Has your question been resolved?

glass finch
#

No but you can go ahead and close it anyways

zinc spear
#

wait you want to close it, bruh i’m tired, you can type .close then

glass finch
#

I guess I'll keep it open if any one decides to help me

weary swan
#

hello hi

#

whats the question uhhh

zinc spear
#

tbh either one

weary swan
#

you would do this with factor by grouping

zinc spear
# glass finch I guess I'll keep it open if any one decides to help me

if you are lost by all the suggestion, i would say prerequisite knowledge is multiplying (foil) and adding polynomials, evaluating them (x^2-1 at x = 2 is 2^2-1 = 4-1 = 3), then the fact that if the polynomial p(x)=0 at a certain value « a » called a root, then you can factor a linear factor (x-a) out of the polynomial perhaps using long division example x^2-1= (x+1)(x-1). Then realizing this fact imply that finding the roots help you factor. then learning about the quadratic formula giving you the roots directly.

vale dockBOT
#

@glass finch Has your question been resolved?

#
Channel closed

Closed by @glass finch

Use .reopen if this was a mistake.

vale dockBOT
#
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.

night patio
#

You roll a standard 6-sided die repeatedly until you get a 5. What is the expected value of the minimum value rolled before (and including) the 5?

night patio
#

@fleet junco Hi. I needed to discuss about this problem

#

Can you help please. I had a doubt.

fleet junco
#

Sure

night patio
#

this was the expected value right?

#

What if we calculate the P(1)

#

and P(2)

#

Like all these 5 terms

#

I basically thought of this

#

to get the probability of getting a minimum of 1 and an n length sequence

#

Now to calculate P(min = 1), I summed P_n (1) from (n = 1 to inf)

#

I get P(1) = 1/2

#

so is this correct?

silk zenith
#

Is that n or m length sequence?

night patio
night patio
night patio
night patio
vale dockBOT
#

@night patio Has your question been resolved?

night patio
#

nvm solved it

#

.close

vale dockBOT
#
Channel closed

Closed by @night patio

Use .reopen if this was a mistake.

fleet junco
#

to do it

#

but

#

its way harder

night patio
#

it was not that hard

#

obviously your method was easier

#

but this works too

#

had to think about it a lot haha

fleet junco
#

oh wow ok

night patio
#

also I found this really cool method on stackexchange

fleet junco
#

but liek yeah thats really good

#

but liek yeah, these sorts of problems are always about splitting

#

into simpler cases

night patio
#

yuppp

#

thankyou for your help ^^

vale dockBOT
#
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.

sour dune
#

I want to understand how vector rotation works and im trying to rotate <1,0> by any angle, i found out that there is multiplication matrix thing. Anyways im trying to figure out the math way to do that but i always get cornered by sin(theta) and cos(theta). I dont get it how to get the value of sin or cos in a math way

quasi valve
#

you mean how to get a numerical result for cos(theta) and sin(theta)?

sour dune
#

yes, not the calculator way

rustic olive
#

θ

quasi valve
#

well there are only a few special angles where you can get an exact number, and even those will require a calculator if you don't want to leave it in terms of sqrt(3) etc

sour dune
#

I know that there is for triangles

brisk lynx
sour dune
#

I want a math solution, like in algebra, plug the values and get back a single digit in that case x,y of an angle

#

is there no formula for that?
i only know cos, sin, tan for triangles where the adjacent, opposite and hypotenuse is used
Im so confused

lyric bloom
ebon glade
#

just because you need a calculator doesnt mean that its not "a math way"

#

the formulas for sin and cos are just more involved than all the other stuff you have seen

#

so you do not ever want to do them by hand

brisk lynx
sour dune
#

well i want to do in programing but if you say so i guess i just use like math library, i just like doing things from scratch

brisk lynx
#

Then just pick any one x,y on that circle

#

Then draw a line from that center which was 0,0 to your point, that's your hypotenuse, and length between them is your radius r

ebon glade
#

I mean, did you also implement things like sqrts and other roots yourself?

#

or did you let a math library handle those

#

same thing

sour dune
ebon glade
#

well then have fun

#

read up on taylor series

brisk lynx
sour dune
#

i only understand how i could use cos sin if i got 2 vectors on unit circle, than i could think about a triangle between <0,0> start and 2 vectors

#

anyways, my only issue is that i wanted to calculate cos and sin in a formula way to get that value between 0-1

ebon glade
#

here are the formulas you need

#

the series are infinitely long but the later terms are tiny so you can cut them off

#

the first 15 or so terms will be enough by far

brisk lynx
#

Yeah as he said what you're looking for is the taylor series expansion

#

It's a way to calculate this stuff with just basic arithmetic, you just have to do it a bunch of times

sour dune
#

oh right the dark moon side is -1

brisk lynx
brisk lynx
#

You do understand what the ! means correct?

sour dune
brisk lynx
#

And the ... you can basically infer

#

Just making sure

sour dune
#

Anyways thanks for help, ill try to implement tailor series and make a vector rotation from scratch.

sour dune
ebon glade
#

yes

#

you can just do a while loop depending on the precision you want

#

tho of course you will run into issues with double/floats anyway

vale dockBOT
#

@sour dune Has your question been resolved?

#
Channel closed

Closed by @sour dune

Use .reopen if this was a mistake.

vale dockBOT
#
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.

karmic hemlock
#

can someone help me simplify 52!/5!47! without the use of a calculator, my answer is 2, 140, 320 while my calc says 2, 598, 960. i simplified the 47 factorial first leaving 48 x 49 x 50 x 51 x 52 in the numerator and 1 x2 x3 x4 x5 in the denominator, so i cancelled out 2 with 48 which leaves 24, 3 with 51 which leaves 14, 4 with 52 which leaves 13, and 5 with 50 which leaves 10. this leaves me with 24 x 49 x 10 x 14 x 13 in the numerator which equals 2,140,320??? why is this wrong

karmic hemlock
#

<@&286206848099549185>

midnight pier
karmic hemlock
#

wdym?

midnight pier
karmic hemlock
#

i have a ti-nspire so not really

#

it can handle some big numbers

slate folio
#

prob rewrite 49*51 as 50^2 - 1

karmic hemlock
#

woudlnt that complicate it more? i dont think its a good idea to add an exponent into the equation

spring jackal
#

51/3 is not 14

vale dockBOT
#

@karmic hemlock Has your question been resolved?

lone furnace
vale dockBOT
#
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.

vale dockBOT
#
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.

somber lintel
#

.close

stark wedge
#

it'll close by itself, just leave it

vale dockBOT
#
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.

sick kernel
#

feynman's trick for integration

vale dockBOT
sick kernel
#

can someone explain it to me as a high schooler

ruby sleet
#

Say you have an integral with set bounds (finite or infinite) and want to compute its value

#

Say $\int_0^\infty \frac{\sin x}{x}dx$

rocky lotusBOT
#

Raphaelisius Maximus MMIII

ruby sleet
#

It would be easier to compute this if, say, the 'x' stuff wasn't there or was replaced with some exponential or trig function

#

Feynman's trick is you introduce an outside parameter

#

So that when you differentiate with respect to it

#

The problem part of your integrand goes away

#

So what if we defined $I(t) = \int_0^\infty e^{-tx} \frac{\sin x}{x}dx$

rocky lotusBOT
#

Raphaelisius Maximus MMIII

ruby sleet
#

As when we differentiate by t

#

Some x gets outside, and will cancel with the x on the denominator

#

So we find $I'(t) = -\int_0^\infty e^{-tx}\sin x dx$

rocky lotusBOT
#

Raphaelisius Maximus MMIII

ruby sleet
ruby sleet
#

Now, the idea is FTC (fundamental theorem of calculus)

#

To find I(0)

#

Find I(some appropriate value of t)

#

And find I'(t) for all t

#

Since we find that I'(t) = -1/(t²+1), I(t) = -arctan(t) + some constant

#

Here the interesting t value is "t = infinity"

#

Then the computation you can do on your own, but that's the gist

vale dockBOT
#

@sick kernel Has your question been resolved?

vale dockBOT
#

@sick kernel Has your question been resolved?

vale dockBOT
#
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.

wraith dew
#

Let KAM be a right triangle with angle K being right angle, side k is 24 cm and side m is 7 cm. Determine the length of side a correct to one decimal. Enter numerical value only.

restive aurora
#

Which angle is K?

#

Is it between sides A and K, M and K?

noble anvil
#

What do we do when we are given two sides of a right angled triangle and asked for the third?

wraith dew
#

the question just says angle k being riight

#

wait here

restive aurora
#

If you have a picture that'd be great

wraith dew
#

this is all it says

#

ive been doing these questions for like 3 hours i cant get them

noble anvil
wraith dew
#

its always off by a decimal or something

restive aurora
tidal swift
#

this sounds like it's calling for a certain law

restive aurora
#

Oh, so you know how to calculate this?

#

!status

vale dockBOT
#
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
wraith dew
#

uh 3

noble anvil
#

Show work

wraith dew
#

a
2
=k
2
−m
2

𝑎
2

24
2

7
2

576

49

527
a
2
=24
2
−7
2
=576−49=527
𝑎

527

22.9

cm
a=
527

≈22.9cm

restive aurora
#

Yeah, can you tell us what your answer was and how you got there?

wraith dew
#

why did it do that

tidal swift
#

oh my goodness

restive aurora
#

Lmao

wraith dew
#

i tried to copy paste what i typed in

noble anvil
#

Send a screenshot

restive aurora
#

Well that's essentially what I got

wraith dew
#

oiaky wait

restive aurora
#

How are you supposed to submit the answer to this question?

wraith dew
restive aurora
#

Is it possible it wants you to enter it exactly? Like sqrt(527)?

wraith dew
#

correct to one decimal

restive aurora
#

Ah

wraith dew
#

numerical value on;ly

restive aurora
#

Well

wraith dew
#

thats all

restive aurora
#

I think you're rounding wrong

noble anvil
#

,calc (527)^(1/2)

rocky lotusBOT
#

Result:

22.956480566498
wraith dew
#

im suppsed to write that whole thing ?

tidal swift
#

no

restive aurora
#

Nonono

tidal swift
#

round to nearest tenth

restive aurora
#

5 rounds up

tidal swift
#

your final answer is xx.x cm

wraith dew
#

23 ?

#

23.0

tidal swift
#

23.0

restive aurora
#

Yeah!

#

Try that

tidal swift
#

must have the .0

#

otherwise you are not meeting question reqs

wraith dew
#

wait but what didi do wrong withrounding on the question

tidal swift
#

you rounded down

restive aurora
#

Oh well look at the 2 decimal places, 22.95

#

To round to 1 decimal place we round up, since the last decimal is 5

#

So 22.(9+1) -> 23.0

wraith dew
restive aurora
#

My local calculator app, Qalculate

wraith dew
#

taken

wraith dew
wraith dew
#

how do you guys know so much about math

restive aurora
#

Lots and lots and lots of practice

wraith dew
#

how old are you guys

tidal swift
#

personally, practice, good out of school teachers, practice, friends, and more practice

restive aurora
#

28

tidal swift
#

and books

tidal swift
noble anvil
wraith dew
tidal swift
#

oh hey, a peer

wraith dew
#

i turned 15 on the 13th

restive aurora
#

Yeah don't worry about being behind, I was a terrible student until I was like 23 and now I'm doing fantastic

noble anvil
#

Welcome to mathcord btw royal MenheraSalute1

wraith dew
#

yeah thanks i appreciate iit

tidal swift
#

i'm still terrible dw

#

together we improve

#

also welcome to the server!

wraith dew
wraith dew
noble anvil
#

!done

vale dockBOT
#

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

noble anvil
#

I'll close it for ya

#

.close

vale dockBOT
#
Channel closed

Closed by @noble anvil

Use .reopen if this was a mistake.

vale dockBOT
#
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.

proper marten
#

can you solve E5=M^A if A=E

vale dockBOT
stark wedge
#

what is E5 supposed to mean?

#

...

#

!xy

vale dockBOT
#

Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.

proper marten
#

i mean E

#

it kept the typos

#

im so sorry

stark wedge
#

post the original question exactly as it was given to you

proper marten
#

E5=M^A if A=E then E5=E1+E2+E3+E4 find M

#

that was the question that was given

opal pendant
#

so they are just variables

proper marten
#

yea

#

...

opal pendant
#

what do u have to find M in terms of

#

cause it wont be a constant value as we dont know the values of anything here

proper marten
#

mass

#

M=mass

opal pendant
#

..

#

why didnt u specify that before

proper marten
#

convert eneergy into mass

#

forgot to tell

opal pendant
#

convert energy into mass?

#

what?

proper marten
#

i meant M^A

#

so can you help me?

#

ive been stuck on this question for a couple 2 days

ebon glade
#

so far this is just a bunch of nonsense

#

there is a lot of context missing

#

from E5=M^E and E5=E1+E2+E3+E4 with no other relationship between all those variables you can do absolutely nothing

proper marten
#

but i can swear he gave me E5=M^A

#

and said M= mass

#

so what do i do?

stark wedge
#

do you have a picture or screenshot of the question? yes or no.

proper marten
#

No

#

And hes my tutor

stark wedge
#

can you contact him again to ask for a clearer statement of the question

proper marten
#

He then said M=4 billion kg

#

Well I dont know how he got that

#

I think Im missing some info

#

And he said 4 billion kg is a approximate that rounded up

#

So can we backtrack to see the missing info or no?

river shale
proper marten
#

he wants his info disclosed

river shale
#

The information is kinda scattered rn, it’d be better for you to rephrase and stick all of the information together.

proper marten
#

so sadly i cant

#

yea i could do that though

river shale
#

Appreciate it, big thanks pandahugg

proper marten
#

E5=M^A if A=E E5=E1+E2+E3+E4 then if we know M=4 billion kg in the equation

#

E5=M^A

#

is that enough info though?

desert knot
#

there's not even a question to answer

proper marten
#

and then what would the mass be then? if E5=M^A

drifting hornet
#

is this part of some physics question?

#

we need the full context

desert knot
#

well apparently the mass would be 4 billion kg

#

since that's what you said 3 messages ago

proper marten
#

typo

#

i think

#

nvm

desert knot
proper marten
#

but still dont know how he got the answer

river shale
#

yeah….better screenshot the messages. It’s alr for you to hide his identity.

#

It’s not gonna work with these information

proper marten
#

also then he said noww found the enegy

#

energy

desert knot
#

my guy this is just absolute nonsense

drifting hornet
#

We know 0 context dude, what energy? Mass of what? What even was the original question? All we have is 2 equations including letters that werent even defined

#

we cant help with this

#

either you have to provide more context, or ask your tutor

proper marten
#

then said E= energy so E1 is E

lyric sundial
#

...

#

Don't you think we know nothing about the context of your question??

proper marten
#

im so sorry

lyric sundial
#

We've been telling you this from the beginning

river shale
#

By any chance, could you provide the original question?

proper marten
#

nah he just said its a challange question

lyric sundial
river shale
lyric sundial
proper marten
#

i mean he said it a simple question

drifting hornet
#

so did your tutor give you the question? Or did you send the question to your tutor asking for help? What's the source of the question?

proper marten
#

nah he sent it to me

river shale
drifting hornet
#

Can you either ss the message (censoring the sender ofc) or write it word for word in here?

proper marten
#

i cant because of the private policy contract would be violated

lyric sundial
#

Then we CAN'T solve your doubt.

river shale
#

Well

drifting hornet
#

Hmm, if everything is supposed to be private, i dont think we can help

river shale
#

Unfortunately

drifting hornet
#

we cant help with a private question we cant even see

#

You'll have to ask your tutor about it

lyric sundial
#

You should understand by yourself that the "info" you've given about the context is too little to understand what you're doing

proper marten
#

Im sorry for the confusion its just always on my mind

#

Because my tutor said that if I get one of the questions of that equation right then I'll easily pass his teachings and wouldn't need anymore tutoring

noble anvil
#

The question is figuring out what the question is pikasunglasses

proper marten
#

In the same boat as yall

#

But atleast we know that acceleration is apart of the equation of energy ...right?

desert knot
proper marten
#

I mean energy5

desert knot
#

No, nobody knows anything like that because you haven't explained anything about the problem whatsoever

noble anvil
#

What is energy 5 woeisme

proper marten
#

Energy5=energy+energy2+energy3+energy4

river shale
proper marten
#

He said yes

#

I mean he did say that when he sent "now find energy"

#

Do i have to use chat gpt?

river shale
#

Alr so, just for these information, what does “E” stand for?

proper marten
#

Energy

river shale
#

Are you looking for E? Or E5

proper marten
#

E

#

Because E5 is energy5

river shale
#

So (4 billion)^E = E1 + E2 + E3 + E4

#

Is this everything?

proper marten
#

Yea

#

I mean no actual

#

Because where would E5 be in the equation if we just swapped it out

river shale
#

yeah, I revised it

proper marten
#

Okay

river shale
#

Is there anything missing?

proper marten
#

E1 is E and thats why we needed E5

river shale
#

Damn….you didn’t mention this earlier

proper marten
#

You see where it gets confusing?

river shale
#

But sure, lemme update the information

river shale
#

What’s your native language btw

#

So (4 billion)^E = E + E2 + E3 + E4

proper marten
#

Yea

river shale
#

What’s your mother tongue

proper marten
#

Idk my native language

#

Got confused between English and Vietnamese

river shale
#

I see

proper marten
#

I keep connecting them to each other

#

But can we answer the equation? Or do we have to ask for more info

river shale
#

Better screenshotted originally from your tutor.

noble anvil
#

You gonna go back to class and the tutors gonna say it was a test to see if you could realise if the info is sufficient or not monkey

proper marten
#

I've tried that method and it didn't work:'"

#

I go up to him and ask that question of is the info sufficient or not?

#

And if that was the question but he didnt answer

#

Also he then said that ^E=Mlog7

ebon glade
#

oh great a random 7 from nowhere

proper marten
#

It meant to be a small 7 but the text font put it back to a big 7

#

Sorry

ebon glade
#

that makes even less sense

proper marten
#

Why do you think im so confused

noble anvil
#

what is a big 7 monkey

ebon glade
#

presumably log_7 vs log(7)

proper marten
#

Log(7)

#

I cant with him sometimes you know?

#

He changes his mind so many times because it used to be log_7

noble anvil
#

get a different tutor then

proper marten
#

But I do get what hes trying to teach me

#

Also is that enough info?

#

I feel like it is

ebon glade
#

this is still nonsense

noble anvil
proper marten
#

Do we times the M with Mlog(7)?

#

Or what do we do

#

Because im out of ideas

#

Wait he got me more info and said that if ^5=Mlog(7) then E=Mlog(7) times the original equation

#

Are we getting somewhere?

river shale
river shale
proper marten
#

So then the original equation was where A wasn't apart of the power

#

the pain

#

Can yall put that in one equation for me please I got so sidetracked with the messages that I forgot what the original equation was

#

And the he said E5=28th of the number of Mlog(7)

#

Number

#

I meant 28th number

ebon glade
#

a random 28th. it gets better

#

on the off-chance that you arent trolling, just fire your tutor

#

nothing of what you said made any sense

proper marten
#

I mean and then he said E5=28th number in Mlog(7) I put the wrong info in

#

That's why

#

That mean we know what E5 equals so then we have to find out what E+E2+E3+E4 is doing in this equation

#

Wait one min while I find out what E2,E3,and E4 is doing

#

..were cooked

#

We are cooked

stark wedge
#

now you are utterly charred

#

you've become a lump of carbon in the oven

#

a very well done steak

#

etc

open abyss
#

just fire this tutor😭

proper marten
#

So basically what he said was that these are all similar equations that equal to a similar rule of the temperature of the sun is the power of all of them in different times zones

#

Of that supposed sun

stark wedge
proper marten
#

Then he gave me time zones

stark wedge
#

or maybe you could finally give us some screenshot of the tutor's message instead of continuing to play broken telephone!!!

ebon glade
#

Ann just give up. its pointless

noble anvil
#

.close

proper marten
#

Lemme finish these please stop texting for a little so we can get all of this in one part of the messages

vale dockBOT
#
Channel closed

Closed by @noble anvil

Use .reopen if this was a mistake.

stark wedge
proper marten
#

Thanks

noble anvil
#

there is 0 progress

#

.reopen

vale dockBOT
#

proper marten
#

Okay so E2=24 and we have to use the time zone of 12:00 July 15

#

As for the rule

#

Then E3=52 and the time zone for the rule is June 7th 12:50

#

2024

#

Then E4=8 and the time zone fo the rule is August 7th 12:30

#

Okay

#

Then he said use our sun of our solar system for a eazy estimate

#

August 2024 for the E4=8

#

Then we calulate

#

Okay I think we can talk now if this gave us all the info for E5=E+E2+E3+E4

#

To slove

#

their all am

#

amd E2=24 has the year of 2020

#

thats all the info i think

#

i need to go calulate all of this

#

wish me lcuk

#

he said it should take a couple hours to a month at least for one of these equations

#

i accidentally did 12:01 am July 15 time zone

#

:"""""

#

and used 2019

river shale
proper marten
#

i used the wrong nuumbers

#

for the first equation

river shale
#

Alr alr, can you put every current information together?

#

We have to accumulate every piece of them

proper marten
#

that was the only one but it was actually E2=24 time zone of 12:00 a.m. July 24 and they are all a.m not pm

#

and at the year of 2016

river shale
#

I assume it’s not a pure physic question, more like a riddle

#

Do you contact your tutor in English or Vietnamese?

proper marten
#

actually in my new language im learning that is french

#

yep

river shale
#

Hmm….

#

How about this, you copy your tutor’s message instead of screenshotting them

#

Messages regarding the question ofc

#

cuz we have helpers that speaks French

proper marten
#

you sure i cant just translate it? because his "French" is too old that i had to ask a special translator to change his wording into actual reading words in english

#

he's even using slang that is not in date with the new ones

river shale
#

We would be upset but at least this explains why the question looks so scattered brain

proper marten
#

i pay extra for a translator in Canada to tell me what he's saying and sometimes she doesn't even know some of the time

#

of wwhat hes saying

#

so what do we do now?

river shale
proper marten
#

what other context do i need to show?

#

or do you need to know

knotty storm
#

bro

#

if the question is supposed to be private

#

why r u telling us thi

#

why r u asking us

proper marten
#

shhh

#

i want to make this help me in secret

knotty storm
#

bruh this guy is obviously trolling

proper marten
#

but not have it were he could take leagal action

knotty storm
#

its a new account

stark wedge
#

since when is he gonna take legal action over a fucking math problem

noble anvil
#

First day on discord and this is what you decide to do

knotty storm
#

because he is a troll

proper marten
#

could i show a legal form on this discord?

#

or does it not let ,e

noble anvil
#

Do not show any identifying information

#

Especially when it's of someone else

proper marten
#

so i cant show his contract? but yall call me a liar

knotty storm
#

show it

proper marten
#

I've been stuck with this crazy guy for so long trying to get at least one question right so i can leave his stupid tutoring

stark wedge
#

wdym "leave his stupid tutoring"

#

can you not... just leave???

proper marten
#

i made it my goal to atleast answer one question

#

and this one wa the most simple of the bunch

stark wedge
#

dude.

#

just leave.

proper marten
#

should i answer it my own?

stark wedge
#

these goofy-ass questions can honestly go fuck themselves

drifting hornet
#

get a better tutor with better questions

proper marten
#

ima try to answer it bymyself

#

trust that ima be back in about 3 years with the answer

haughty fiber
#

lmao just read this thread

#

this is nonsensical

drifting hornet
haughty fiber
#

@proper marten I think the complaint is just simply that you're not explaining the question clearly, and in fact, you actively refuse to

#

mathematics is more collaboration than competition

#

if you can't help us help you, it will never work out

proper marten
#

trust and close help please

#

close.

drifting hornet
#

.close

vale dockBOT
#
Channel closed

Closed by @drifting hornet

Use .reopen if this was a mistake.

river shale
#

.close

#

bruh, got sniped

haughty fiber
#

lmao

proper marten
#

,close

#

.close

drifting hornet
#

It's closed already

#

just wait

#

or keep writing .close. whatever you wish

vale dockBOT
#
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.

open niche
#

The integral on the right has a_k complex numbers so what would its integral be some solutions use just ln and not complex log

open niche
#

,w int(1/(x^24 +1)) dx

open niche
#

Here for example it uses half csc half of the logs (assuming complex ones mixed so thst its real inside )

open niche
open niche
storm perch
rocky lotusBOT
storm perch
open niche
#

But ln isnt real ln its complex ln

#

When lnz = ln|z| + i arg(z)

open niche
#

Cause it doesn't mention base

storm perch
storm perch
storm perch
vale dockBOT
#

@open niche Has your question been resolved?

open niche
storm perch
open niche
open niche
#

e^iθ or csc

open niche
#

Whats best form you can use for representing all roots ak

#

e^iθ or csc

#

For easier expansion

worn sparrow
#

i would say something like

#

$\eta_k$ with a note "where $\eta_k, k=0,1,...,23$ are the 24th roots of -1

rocky lotusBOT
#

gfauxpas

vale dockBOT
#

@open niche Has your question been resolved?

open niche
#

Just instead of η i have a