#help-0
1 messages · Page 62 of 1
yeah, that works too, lots of way here, since we can be quite flexible here with all the trig identites available
im kinda interested by this one. end up getting [sinx*2sqrt(1+cosx)] / U. Im asuming that you can write it as [sin(x) * 2U] / U ?
write sinx as 2sin(x/2)cos(x/2)
and 1+cos(x) as 2cos^2(x/2)
simplify and put u=sin(x/2)
eh no, the idea was that the derivative of sqrt(1+cosx) is -sin(x)/(2sqrt(1+cosx)), so this takes care of the sinx on the numerator and the denominator as well
cancelling to only sinx
Which is why it works so well
to which you can rewrite that in terms of cosx and then just sub u in
What did you find not so straightforward with it btw ?
the rewriting sinx to sub u in might not be very straight-foward to those who have not done a lot of substitutions
yeah but its the best way
as in, people who just starts out do not see it coming
lots of times you need to use half angle formulae in integration
Honestly the algebra for it is messing me up. Im trying to manipulate the half angle identities to get 2sin(x/2)cos(x/2) and just not getting it
well then
okay I see now. You can express sin(x) as sin(2(x/2))
see we know 2sinxcosx = sin2x
if we sub in 2x = u
u = x/2
or the thing above
@spring spruce did you get it
the integration
yeah i got 1/3sqrt(2)
cool
any tips to recongnize this stuff. Because for me at least. Its been awhile since I've had to use some of these trig identities. and expressing x as (x/2 +x/2) or (2(x/2) and then expanding isnt really intuitive. It might also be the fact I havent slept
get some sleep
identification comes with practice
no tips really
you need to see what you can transform it into
I think Ill do that after I finish this assignment. Apparently 11 assignments a week plus a lab and a fucking graded review for a exam(idk) is considered reasonable
.close
Closed by @spring spruce
Use .reopen if this was a mistake.
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.
factor of 956
any idea where to start
Start from what number definitely divides 956
HUH
239 * 2^2
@tropic junco Has your question been resolved?
Closed by @tropic junco
Use .reopen if this was a mistake.
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.
let S(n) = n+r for every rational number n
forall n in R. P(n) -> P(S(n))
forall n' in (0, r]. P(n')
Therefore, for all n in R+, P(n).
does this actually mean P holds for all of R+?
By euclidian division yes
Except for 0, which I suppose you don't include in R+ here
Wait no
You said S(n) is defined for rational n
So it doesn't work for irrationals
Oh right
But actually it still does
it still does what
Actually it's worse

seems like P holds for all positive reals
Yes
i think r is supposed to be <= the upper bound of the range on base cases
this is like scuffed induction
You've got (0, r] + rN, which is thus (0, +inf)
No because it's just euclidian division
As I said earlier
mean
wait can u even do that
apparently, but you need to show that P holds for an interval, not just under a well order
does this have a name though?
@candid comet Has your question been resolved?
@candid comet Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
i really dont know how to start on this question
this one as well
Physics but ok
here only for calculus?
make fbd
Closed by @autumn reef
Use .reopen if this was a mistake.
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.
hello everyone, how did this happen? what type of rule/formula is this
Closed by @modern lark
Use .reopen if this was a mistake.
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.
hello can u help me soolve this one please
lim as x approaches 0 ( (x+tanx)/sinx)
note
$\frac{x+tan\left(x\right)}{sin\left(x\right)}=\frac{x}{sin\left(x\right)}+\frac{tan\left(x\right)}{sin\left(x\right)}$
Dav1d
do you know the limit of x/sin(x)?
tan = sin/cos
yes
yep
and whats cos(0)?
1?
yep, so 1/cos(x) --> 1/1 as x-->0
yes
sin(x)/x, right?
,w limit (x+tan(x))/sin(x), x->0
you didnt get 2?
yes
i was wrong at something i multiplied the numbers
not add huhu
anyways thank youu david!!
You're welcome
@low current Has your question been resolved?
Closed by @low current
Use .reopen if this was a mistake.
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.
Hi
How should I do this?
(1 - cos(a) + cos^2(a)) (1 + cos(a) + cos^2(a)) (sin(a))
A team leader has 16 tickets with upcoming deadlines. He has nine developers at his disposal. In how many ways can the team leader assign tickets to developers if each developer must get at least one ticket to avoid being out of work? There is no need to discriminate between tickets, only the number of tickets is important.
Hint: First, determine the number of tickets after a team leader distributes one ticket to each developer. Then, apply the formula of combinations with repetition. Use bars to distinguish between developers and stars to denote the remaining number of tickets.
this channel is occupied
how can I find available channel? I read that I shall post in help-0 channel and the only one I found was this.
at math help available
@leaden field help - 12 is open you can send you question there..
@vale pulsar Has your question been resolved?
.close
Closed by @vale pulsar
Use .reopen if this was a mistake.
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.
the difference in one subtraction is 440 what will be the difference if the decreasing 30 is increased and the output is decreased by 20?
My homework
@nocturne trout Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
how would i find lim{x->3} of
i know i need to use the squeeze theorem but im not sure how
What's the limit of the left function
would you just use direct substitution to find that
Yes
18 - 33 + 17 is not 32
yeah i know i made a mistake i just wanted to clarify if it was -33
Yes
Yeah sorry
Yes
Closed by @crimson blade
Use .reopen if this was a mistake.
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.
since plog(1/(p+n)=-plog(n+p)?
You mean on the ρlog(ρ + μ)?
log(1/n) = -log(n)
or okay i thought it would be double minus since we are swapping the terms
and thus a plus sign but of course not; as we are taking the sum in the first equation its the same thing
then doing the inverse in the log swaps the sign
Yes 
Closed due to the original message being deleted
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.
what are two numbers that can become the product of 24 and the sum of 14
just make 2 equations xy=24 and x+y=14, then substitute y in terms of x in the other equation
like x+(24/x)=14
or x(14-x)=24
.close
Closed by @dense lily
Use .reopen if this was a mistake.
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.
.reopen
.close
The volume of a certain solution was
reduced by 30% and then diluted by
adding 100ml of water. If the volume
of final solution is 50% more than the
original volume, then, what was the
initial volume of the solution (in ml)?
help me with it
got one equation that is initial value 1.375x cause i didn't supposed 100% be actual value
@peak quiver Has your question been resolved?
@peak quiver Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
how to find a?
@viscid mesa Has your question been resolved?
@lone heart
Extend d1 to meet line AB, then find some angles by the parallel lines and proceed 🙂
@viscid mesa Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
me

so the question is to prove through mathematical induction that Un >= 1/3
And I did this
is this correct?
better pic
4/7 isnt greater than 3/4 is it?
it would only make sense if it was
oh i know hold on
this should be it right?
Yes this is nice
Ok thanks

Alright good night 
Closed by @last onyx
Use .reopen if this was a mistake.
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.
@mental coyote plz help
Omg
Closed due to the original message being deleted
.close
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.
How many subsets of {1,2,3,4,5,6}are of size three which have 1 but not 2?
@alpine sable Has your question been resolved?
Closed by @feral raft
Use .reopen if this was a mistake.
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.
No idea how to solve
@shell urchin Has your question been resolved?
@shell urchin Has your question been resolved?
@shell urchin Has your question been resolved?
@shell urchin Has your question been resolved?
@shell urchin Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
Btw don't ping helpers before 15 minutes
where is kl + sk - sa btw
it is not said
Problem 5 on the first image
it's from 5.
ye
AS maybe
Well first try to find the sum of the first two vectors
Would it not be SL?
When you put the two together, kl + sk
You can write it like sk + kl
K being the middle end of one and the beginning of the other
it's LS?
LS yes sorry
oh ye
so AS
i meant u get as after subtracting
Oh
Yeah
Because it can be written as a sum
And then you should be able to get it from there
SL + AS
AS + SL
Which gives AL
AB+BC=AC
Yes
AB-BC=CB
Kk
Closed by @haughty fiber
Use .reopen if this was a mistake.
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.
I got 320 but the answer is 326
Hmmm. No
look it up
tldr, look at the row with the black circle in it
the first entry, there is only 1 way to get there (all along the side), but the second one there are 4 ways to get there (count them)... it follows the pattern found in pascals triangle that I happen to be very familiar with....
so, knowing this we can work out how many "ways" to get to the other circles from each one of those
lets call the row with the black circle row 1, and the row at the very bottom row 2 just to avoid confusion
you cant get to the first entry of row 2 from row 1 entry 2 because it cant reach
so there is only 1 way to get to row 2 entry 1
If we imagine in row 1 that there are mini pascal triangle starting from each entry, you should have some idea of what the value for each bottom row node is
So consider, row 1 entry 1 as having a value of 1 and row 1 entry 2 as having a value of 4...
Bottom row
Entry 1: 1 - since it can only be reached by row1 entry 1 once
Entry 2: 7 - since it can be reached from row 1 entry 1 in 3 ways, and via row 1 entry 2 in 1 way (but that must be multiplied by 4 so hense final answer is 7)
Entry 3: 15 (3 ways from entry 1, 3 ways from entry 2)
Entry 4: 17
then just double it cause it'll be same for other 4 last entries
(1+7+15+17) times 2
I make it 80
80*
oof
I only calculated according to the image and not to 10th row, ignore all that :I
Yeah no worries. They didn’t; show all I don’t know why :/
How does my answer look?
I did just think of another way around the problem though... give me a sec
Ok
so each row in pascals triangle (usually) adds up to 2^n right where n is the row number (and the first entry row number is 0)?
if they mean that the first entry on that sequence is the "first row" rather than the "zeronth" row like regular pascals triangle then we can simply add two rows to this and calculate:
1 times 2^5
+
4 times 2^5
+
4 times 2^5
+
1 times 2^5
10 times 32
=320
you sure 326? I think you got it right
i agree with you, doesnt make sense
each row will add up to 2^n in pascals triangle where the first entry "row" n=0
in this scenario you have 4 pascals triangles with 6 rows total, so n will be 5
Since we know by pascals triangle or binomial theory ( nCk) that each of those traingles will start with a 1 or 4 as described above...
nope, the papers wrong lol. Prove it and complain to your teacher, make sure you tell them though else they might mark you as wrong
Yeah, actually there was another question wrong on another paper so…
funny story, im not amazing amazing but when I was a kid I made the newspapers for a math discovery to do with the freaking triangle
Haha that is a coincidence
Answer is 38 but I have no idea
technically the answer is infinity but you end up with a complex number
not sure how to do this one at the tope of my head
I'd probably try and play around with it,
Set y= expression and see what you can do
Ok thanks
also, 38 would lead to a complex number aswell cause of the argument of the second part of the equation
so if your gonna have a complex number, go for x equals infinity
but, since Im gonna guess they dont want that, just use X=59
try X=361
sorry, misread the first time
I think, you need to make both halfs of the expression equal each other
X=420
sqrt(781-420) +sqrt(420-59)
= sqrt(361) + sqrt(361)
= 2 times sqrt(361)
= 2 times 19
= 38
Ok but how to know to make x = 420?
thats not what the quastion is
its just find the maximum value of the expression
the maximum value is 38 and it occurs when X=420
you know to make it 420 because you're making both parts of the expression equal
so you are left with sqrt(361) + sqrt(361)
Thanks
@fathom forum Has your question been resolved?
Closed by @fathom forum
Use .reopen if this was a mistake.
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.
im not sure how to do this question
Start with the fact that a sum of square numbers is more than or equal to 0
n ull get everything on the left
That will give you your initial inequality
then just have like 1 extra term n u good
If you play around a bit with that you’ll get the CS ineq
oh nvm i think what i said is wrong i read it wrong oops
oh all good
¯_(ツ)_/¯
@earnest oriole Has your question been resolved?
Closed by @earnest oriole
Use .reopen if this was a mistake.
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.
What's the misprint here ?
Na its from limits
How are they both equal to the same result?
the first one looks like the second one when n=1
Yes but this book is just stating the results from the limits so...i beleive that j is a somewhat a typo
the first one is right
Yes but what about the second one ?
you shouldn't be dividing by n, you should be multiplying by a^(n-1)
see, i) and j) are equivalent
since we know that i) is correct, that must mean that j) is equivalent, so you can equate both sides (the answers on both sides) and see that they are not equal
This is just the theory part of the book 💀💀
also, when you multiply a^(m-n) by a^(n-1) you end up with a^(m-1)
to be fair, Im not 100% sure
I typed in the expression on wolfram which gave me the left hand side
Im not sure if theres some specific theory where that J) is the case, all I did was go by what I know works; perhaps there is something extra to the limit that makes that happen though
Closed by @acoustic mirage
Use .reopen if this was a mistake.
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.
Notice that the angle ACB is 90 degrees
Hmm no idea as well
Ok
<adc=(360-(75*2))/2
use that in triangle adc all angles added each other is 180 and you can find <dca
and <dca=180-33-105=42 deg
Why 75 *2?
its because the agle is in the curcle
its not a central angle
and you have formulas for these types of angle
Sum of opposite angles of a cyclic quadrilateral is 180°
yes you can use this too
welcome
Np
are you in class having test?
Ok thanks
np
@fathom forum Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
use l'hopitals rule
@celest minnow Has your question been resolved?
Closed by @celest minnow
Use .reopen if this was a mistake.
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.
I need help
i need help someone
Whether such functions exist which are differentiable at infinite many points and non-differentiable
at infinite many points. If yes, give any two examples. If no, justify your response.
its a calculus question
Sorry, this channel is already taken:)
@swift sky with
Ik which are discontinuous at infinite points
cant there be a function which has both
contineous at infinite and discontineous at infinite
It was dirichlet function
So is this not my channel?
It's alright yall can continue here
I will just go somewhere else.
Nono ask
30 people (including A, B, C) randomly put themselves in a queue. What is the probability that A always gets ahead of both B and C?
I have some ideas but I am not sure
take your time, no worries
Okay let me explain how far Ive come so far
I divided the problem in different steps
@swift sky Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
30 people (including A, B, C) randomly put themselves in a queue. What is the probability that A always gets ahead of both B and C?
I have some ideas but I am not sure
So far I have tried solving the question this way
by diving it to different steps
I mean if A is in the first place then there is 29! way of placing the rest
If A is in the second place then there is 28! way of placing the rest and then 2! way placing A and the first person before everyone else
If A is in the third place then there is 27! ways of placing the rest and then 3! way placing A and the first 2 ppl
If A is in the forth place then there is 26! ways of placing the rest and then 4! way placing A and the first 3 ppl
And then I should do this until I get to 28, because that last case is the case where B and C are the last.
And then I should add these outcomes and divide it by 30!
I don't know if this is correct but even if it was, there has gotta be a shorter way to solve this question so I need yall help with that.
there are 6 ways they can be placed relative to each other, it's just 2/6
What do you mean?
and like it's 1/3 because there are three of them, it has to be equal chances for each to be first
you asked for short
xd
By symmetry, it can't be anything but 1/3: they are all equally likely to be first
Yeah I want a short way of doing it but I don't understand what you meant here.
by symmetry A is first = B is first = C is first
then, there's no way no one is first (or multiple people are)
which means X+X+X = 1, X = 1/3
I don't know what "symmetry" means in this case, but what about the rest of the 27 people in the queue?
the other people can't just increase one of ABC chances preferentially
whatever they do, it happens equally to all three
sorry Im a bit slow so I still don't understand.
Yeah they all have the same chance of being first but what is the chance that on of them for example A is always before them?
Visualize the list of 30 people. Select A, B, C from them. Compare their order.
That doesn't require knowing anything about the other 27 people. It doesn't even matter A,B,C were. All that matters and what their order is when you extract them
Therefore it's as if there was only A, B and C
it's 1/3 because they all have the same chance of being first
that's the reason, there's one way to divide one into 3 there are no ooptions here
I like this question
also you're adding always which makes it an absurd question, it doesn;t happen always, we're just supposed to say 0, it's not probabilistic
Say you took part in a national contest with your friend. You did great and he thinks he did poorly. You estimate there's a 70% chance you did better than him.
This probability doesn't depend at all on whether you were the only 2 people competing, or if there were 100 or 10000.
So you can just remove other people from the equation, they don't matter
Now say I pick 2 people who participated, at random. I call the first one A and the second one B.
What's the probability A is ranked higher than B ?
The answer is 1/2: there's no reason for my 1st random pick to be better/worse than my 2nd. Rigorously you can say that you were equally likely to have picked B first and A second. So there's no reason your first pick should be a stronger person
That last argument is what we mean when we say there's symmetry in this problem: the roles are interchangeable
This also applies with more people: you chose them at random, there's no reason the order in which you pick them makes a difference
@swift sky Has your question been resolved?
I understand what you guys mean now but I feel like the question is more about permutation than just probability too. If I calculate my earlies try, will i get 1/3?
1/3 is the answer yes
But I mean is my try correct, if you scroll up, you will how i started solving it, and i am wondering if that is right even if it is long
It should work. Probability is, under a uniform distribution, by definition (when there's a finite number of cases), just the ratio of cases in which the property is verified over the number of cases in which it is not.
But here that would be incredibly difficult to compute, especially without a calculator
I just did calculated it and got 0.0385156546
That's wrong. It's (ways of choosing the people before A) * (permutations of people before A) * (permutations of people after A)
You forgot the 1st one
Which must then be modified to account for the specific positioning of B and C
So it's actually (30-A)P2 * (28-A)C(A-1) * (A-1)! * (28-A)!
With A going from 1 to 30
That hopefully yields 1/3
,w sum for A = 1 to 30 of ((30-A)(29-A) * ((28-A) choose (A-1)) * (A-1)! * (28-A)!)
Pain
Let me try it again, and get back to you
@swift sky Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
<@&286206848099549185>
You can only use the helpers tag after 15 minutes have passed
oh sry
Just l'hopital
not allowed
Then what is allowed
traditional way
yes
What chapter is this problem from
limit and continuity
Probably some trig identity then
there is one
lim to 0 arctanx/x =1
.close
Closed by @rapid flare
Use .reopen if this was a mistake.
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.
What am I supposed to with that
Aight then
now
...
helpme
.close
Closed by @last ether
Use .reopen if this was a mistake.
Don't people to help you
bruh
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.
How to solve this please
I need to prove it with calculations
To prove what?
You can use intermediate value theorem
ivt to show at least one solution exists
derivative to show its mono so it only has that one
what were the exact instructions
to show that it has a solution or exactly one real solution
doesn't hurt to post and some people (not me) can understand french
Yes but I am also on the website of the book
So I went ahead to find the answer of it
And I find it was the b (the equation has 1 solution)
But since i did nt learn the method i did nt knew how to do it
But now i am gonna learn it for sure
so you haven't done any calculus yet?
They were not good
technically you don't need it if you're familiar with how common functions behave
e^x is an increasing function
sqrt(x) is also an increasing function
True
hence f(x) is an increasing function
And minus 3 is removing values
doesn't affect growth rate
I hesitated between the fact that the function has a root or none
ivt to show at least one solution exists
But without the proper method it was impossible to demonstrate it at 100%
Ty tho
Without you i would probably have spent a lot of time on this
you can sub 0 which is convenient to use and also gives lowest value of the function
and e^x + sqrt(x) - 3 is clearly positive for an arbitrarily large value of x
@stiff horizon Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
how to factor this?
Where are you stuck?
Try to guess one root and solve the quadratic
the whole thing, I dont really know how to start factoring this expression
There is an easy to find one
cubic formula hope that at least one root is rational and use rational root thm
I don't really understand how to start the process of factoring this
You can either use cubic formula if you know it
Or try to guess a root and then do long division to factor it in a linear term and a quadratic
hope that at least one root is rational and use rational root thm
Closed by @shell pasture
Use .reopen if this was a mistake.
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.
I dont understand this question
3(x + y) = y. If (x, y) is a solution to the equation above and y cannot equal 0, what is the ratio x/y?
I know i'm supposed to find what x/y is equal to, but how?
im stuck at 3x = -2y
not sure what to do after that
make one side x/y
how
move the y over to the LHS
and then?
what do you get?
y=-3x/2
no move the entire thing over
put x and y on the same side
because you want to know x/y
can you show me
ax = by
ax / by = by / by
ax / by = 1
i rly dont understand that
you're dividing both sides by by
where b is just the coefficient
yeah
how did the negative disappear
you gotta use the reciprocal
$$\frac{3x}{-2y} = 1$$
Tronsi
how do you get rid of the -3/2
yes
multiplying by -2/3 and dividing by -3/2 are the same
@trail terrace Has your question been resolved?
Closed by @trail terrace
Use .reopen if this was a mistake.
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.
so i have a practice sheet on using trig identities, and i'm a bit confused
this question states that cscx=-sqrt5 and cosx < 0, and i need to find sin2x, cos2x, sin x/2, and tanx/2
all this in mind, how would i find the adjacent side of the triangle (to find cosine)
wouldn't it be some stupid number
wait i'm being dumb, it would just be sqrt24
.close
Closed by @real pasture
Use .reopen if this was a mistake.
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.
Which of the following 5 relations does not hold in every triangle ABC?
translate what?
prob A+B+C= 180?
yes ok so degree
yeah
try using A+B+C=180 to prove or disprove the options
you get B+C = 180-A for example, then plug it into the first 3 options and see what happens
which 3 options
well i guess the idea works for all
the first one for example you get
sin(A) = sin(180-A)
and either you already know that from your table of formulas, or you can just get it by using sin(x-y) = sin(x)cos(y)-cos(x)sin(y)
sin(180-A) = sin(180)cos(A) - cos(180)sin(A) = 0*cos(A) - (-1)sin(A) = sin(A)
so i gotta prove the 3 options for every single answer?
no maybe i formulated that wrong, i meant first three answers
so what do i gotta write for the first one
that it does hold, so its not the right answer
and for the second one
do the same again:
cos(A) = cos(B+C)
cos(A) = cos(180-A)
cos(A) = -cos(A)
so it does not hold and its one of the correct answers
ohh wait i read that incorrectly my fault
cos(2A) = cos(2(B+C))
cos(2A) = cos(2(180-A))
cos(2A) = cos(360-2A)
cos(2A) = cos(-2A)
cos(2A) = cos(2A)
so it does hold
okay third one
for C however you get
tan((B+C)/2) = tan((180-A)/2) = tan(90-A/2) = sin(90-A/2)/cos(90-A/2) = cos(A/2)/sin(A/2) = cot(A/2)
and ofc tan ≠ cot
just try, for D use
A+C = 180-B
no pls can u do it
and -A-C = -180+B
plug them in, its quick
i dont understand anything of this
you get cos(-2B) = cos(2B) which is equal
can you do the steps
do you know how A+C = 180-B?
no
A+B+C = 180 yes?
yes but u dont need to explain it
and then cos(A-B+C) plugging it in we get cos(-B+180-B) = cos(180-2B) = -cos(2B)
and cos(B-A-C) plugging it in we get cos(B-180+B) = cos(2B-180) = -cos(2B)
and the last one?
plug in B+C=180-A you get
sin((B+C)/2) = sin((180-A)/2) = sin(90-A/2) = cos(A/2)
not rly i would open a new channel
Closed by @wind pawn
Use .reopen if this was a mistake.
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.
3
@trim beacon Has your question been resolved?
@trim beacon Has your question been resolved?
Closed by @trim beacon
Use .reopen if this was a mistake.
.reopen
✅
Round 2310.7 to 1 significant figure
@trim beacon Has your question been resolved?
@trim beacon Has your question been resolved?
@trim beacon Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
what is (3i)^3/(2i)^4
$\frac{(3i)^3}{(2i)^4}$. You know the rule on powers of $i$, just apply them.
3317
what😭
i dont know how to type the division sign
i didnt mean for it to be a fraction
the i represents an imaginary number
$i=\sqrt{-1}\rightarrow i^2=-1$.
3317
So you're not dividing anything?
With this in hand, it's quite easy to derive $i^1$, $i^2$, $i^3$, $i^4$,$\cdots$
3317
yes i know that but like i simplified it and i got 9i^3 divided by 8i^4
what else do i dooo
$i^1=1$,$i^2=-1$,$i^3=-i$,$i^4=i^1=4$.
3317
The pattern keeps going.
so what does 9-i divided by 8(1) mean
$9-i$ is the complex number $9+0i$ less $0+1i$, I'm sure that's not what you're trying to notate. Notation can deceive if used incorrectly. If you mean nine times negative i, then it'd be $-9i$.
3317
Literally means $\frac{-9i}{8}$.
3317
Divide the $-9$ by $8$ and multiply it by $i$. That's your result.
3317
Not really, but many people prefer it in that way.
Fractions are pretty much beautified divisions.
Glad to help.
.close
Closed by @analog shadow
Use .reopen if this was a mistake.
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.
This is the diagram
The question
Firstly I don't understand what they mean by "radii"
Is it radius?
or something
yea
radii is radius
plural singualr form
english stuff
i think radii is plural
Oh yeah
yes
just use iso tri
full form??
isoceles trianglw
hm?
,w 180-72
54
ye
Closed by @stiff surge
Use .reopen if this was a mistake.
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.
Hi, just need some help especially on the second part. Already have an answer for A just unsure if its correct.
@alpine sable Has your question been resolved?
@alpine sable Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
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.
I don’t understand how they achieved the integer -72. Can someone please explain?
from the third line
u have -10y+75+4y=3 right
so we want all pronumerals on one side and all numbers on the other side
so they subtracted 75 from both sides hence -72
Closed by @carmine chasm
Use .reopen if this was a mistake.
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.
hi im doing parabola's and i need to know how to find the x intercept of y = x^2 + 6x
what's the first thing you'd generally do when finding x-intercepts
setting y to 0 doesn't wipe that 6 from existence
but dont u have to divide 0 by 6
no?
oh
you're skipping ahead and doing stuff you're not supposed to
the first step, set y=0 (and doing nothing else) gives you
x^2 + 6x = 0
yep
the left side is easily factorable
no
oh
where are you getting that idea
the first thing you'd usually look for when factoring is whether all your terms have a common factor(s)
identify it/them and factor that out
x(x+6)
yes
so what do i do now
your equation will be
x(x+6) = 0
then apply zero product property/null factor theorem
u get x+6 = 0
that's only part of it
x = -6
i honestly dont know what im missing
when will ab=0
when one or the other equals 0
x = 6 or x = -6 ?
x^2 + 6x
no
not what i'm asking for
ab = a * b
supposedly when you said
when one or the other equals 0
you meant a=0 or b=0
similarly
x(x+6) = ?
0
x(x+6) = (x+6) * what
2
no
x
alright
and for x(x+6) = 0
when one or the other equals 0
x intercept = roots of equation
so what do i do now
how can product of two numbers be zero?
apply
ab=0
supposedly when you said
when one or the other equals 0
you meant a=0 or b=0
use common sense to build ur concept
do the same thing here
wait what do i do exactly
ab=0
supposedly when you said
when one or the other equals 0
you meant a=0 or b=0
right?
yeah
do the exact same thing for x(x+6) = 0
so does x = 0
over here a = x and b = x+6
two roots
x = 0 and x =?
6
overall you'll have
x = 0 OR x+6 = 0



