#help-4
1 messages · Page 37 of 1
Ohh ok
4!= 12
120
also we can say (5!/2!)/3! right?
Yes
yes
Group 1 (A, B, C, D):
ABCD, ABDC, ACBD, ACDB, ADBC, ADCB,
BACD, BADC, BCAD, BCDA, BDAC, BDCA,
CABD, CADB, CBAD, CBDA, CDAB, CDBA,
DABC, DACB, DBAC, DBCA, DCAB, DCBA
Group 2 (A, B, C, E):
ABCE, ABEC, ACBE, ACEB, AEBC, AECB,
BACE, BAEC, BCAE, BCEA, BEAC, BECA,
CABE, CAEB, CBAE, CBEA, CEAB, CEBA,
EABC, EACB, EBAC, EBCA, ECAB, ECBA
Group 3 (A, B, D, E):
ABDE, ABED, ADBE, ADEB, AEBD, AEDB,
BADE, BAED, BDAE, BDEA, BEAD, BEDA,
DABE, DAEB, DBAE, DBEA, DEAB, DEBA,
EABD, EADB, EBAD, EBDA, EDAB, EDBA
Group 4 (A, C, D, E):
ACDE, ACED, ADCE, ADEC, AECD, AEDC,
CADE, CAED, CDAC, CDEA, CEAD, CEDA,
DACE, DAEC, DCAE, DCEA, DEAC, DECA,
EACD, EADC, ECAD, ECDA, EDAC, EDCA
Group 5 (B, C, D, E):
BCDE, BCED, BDCE, BDEC, BECD, BEDC,
CBDE, CBED, CDBE, CDEB, CEBD, CEDB,
DBCE, DBEC, DCBE, DCEB, DEBC, DECB,
EBCD, EBDC, ECBD, ECDB, EDBC, EDCB
these 120 right?
Yes I suppose
Wait wait
to get the number of groups
Can you elaborate this
yes can you give me 5 mins, I was busy with something important
sorry
@misty vessel Has your question been resolved?
its the same as 5C4 or a combination right?
yes
oo okayy thanks
I was trying to show him how to get the combinations result
owhhh
@misty vessel
Yes
Sry sey
Sry
Can we continue
My bad for showing up late
@night patio you there?
yes hi
Okay we have these 120 permutations
in case of 4-digit or 4-length permutations using the 5 digits ABCDE
Ok
you can make 120 4-length permutations from these 5 digits using the formula 5!/4!
right?
now can you see like when you do 5 * 4 * 3 * 2
you make these pairs
Yes ok
and we can arrange the pairs in this way
these groups
each group has combinations
which are permuatations of each other
Ok
like group 1 contains the combination of ABCD
Yes
group 2 contains ABCE
Yes
now i know that we are making 4-length permuations
so i will get 4! permutations for each combination
right?
so if each group has 4! = 24 permutations
and I know that total permutations which is 5!/4! = 120
Yes
now look at the other cases before
I gt it
in the case where we made 3-length permutations
Group 1 (A, B, C):
ABC, ACB, BAC, BCA, CAB, CBA
Group 2 (A, B, D):
ABD, ADB, BAD, BDA, DAB, DBA
Group 3 (A, B, E):
ABE, AEB, BAE, BEA, EAB, EBA
Group 4 (A, C, D):
ACD, ADC, CAD, CDA, DAC, DCA
Group 5 (A, C, E):
ACE, AEC, CAE, CEA, EAC, ECA
Group 6 (A, D, E):
ADE, AED, DAE, DEA, EAD, EDA
Group 7 (B, C, D):
BCD, BDC, CBD, CDB, DBC, DCB
Group 8 (B, C, E):
BCE, BEC, CBE, CEB, EBC, ECB
Group 9 (B, D, E):
BDE, BED, DBE, DEB, EBD, EDB
Group 10 (C, D, E):
CDE, CED, DCE, DEC, ECD, EDC
we had this
Yes
Because that's the maximum number of possible arrangements of them
Yea
and I know there are a total of 5!/2! = 5 * 4 * 3 = 60 3-length permutations
Ok
so I divide 60 by 3!
because i know that each group would have got permuted in 3! ways when I did 5 * 4 * 3
so 60/6 = 10
Yes right
we get 10 groups
and you can see we have 10 groups
Yeah I get it now
Now we can say
we just found a method
to make k-length combinations from n distinct objects
like you now know how to calculate the number of 3-length combinations from 5 distinct objects right
Right
Closed due to timeout
Use .reopen if this was a mistake.
small correction
the formula you said earlier
n!/(k-1)!
it should be
n!/(n-k)!
for k-length permutations
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.
@misty vessel do .reopen
Wha 😂
where were we
Ohh ok
yes you know what n!/(n-k)! gives us right
like if i want to know number of 3-length perms for 5 digits
I will get 5 * 4 * 3
or 5!/2!
Yes
n!/(n-k)!
Ok
this is general formula for n objects and k length
yes
Hey wait
now notice
yes
I am trying to understand but I am really sleepy and when I am sleepy, I am sleepy
yes last thing
😂
like this
Ah ok
each 3-length combination is permuted 3! times
so each k-length combination would have permuted k! times
and we can group them together
Ohh ok
we have n!/(n-k)! total perms
Ohh okaye
Yes
this will give you the total number of combinations
Ohhh
like if i tell you there are 10 students in a class
How many groups of 2 can you make?
thats just 10!/(2! 8!)
Yes
these are the total number of combinations
do you get what is the difference between permutations and combinations now?
this is usually known as n choose k
what we did is we derived it
you can skip the derivation if you want
but i like it because it gives a lot of intuition
hi
we just derived it right?
Like with all the sentences?
this formula
.
no we know that
Ok
there are n!/(n-k)! total k-length permutations for n distinct objects
do you understand this part?
now each k-length permutation can be permuted in k! ways
Yeah
so we have k! duplicates or permutations of each k-length sequence
all good hahaha
.close
Closed by @night patio
Use .reopen if this was a mistake.
hi
hehe 😅 why do u say so?
jk 😭
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 am not sure how to get ax^2 and bx, i know that c = -1
You could e.g. get a set of simultaneous equations by the fact that -1 and 4 are roots
ah yea i tried that but i kept getting stuck cause they = 0
im kinda rusty on simulatanious eqs
They being the output you find?
Did you rearrange the equations you found after you substituted -1 and 4 into those, and setting the output equal to zero? You could get them closer to the "usual" form that simultaneous equations come in, and that may make it better(?)
i found the solution online too
i mean i did some of it
just wasnt sure on last part
the reason why there is a 1/4 is because we had to transform x^2 - 3x - 4
a stretch parallel to the y axis by scale factor of 1/4
so that the -4 (this is the y intercept for x^2 - 3x - 4) can turn into -1 (our c which is the y intercept we want)
yes thank you
@midnight pier 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 do I do question 19 with ncr and is ncr an optimal way to do this if my concern is speed?
What's ncr?
nCr is way to type the binomial coefficient (n choose r)
n!/r!(n-r)!
Idek what npr is and what it does tbh
Might learn it later
But is ncr efficient for this question or does it make it harder?
Tbh I kinda forgot this slightly
nPr is for permutations and is n!/(n-r)!
Does anyone know a good algorithm for checking if there are roots in a specific interval of a non-linear function?
Ts not an available channel 🙏
theres a lot of reading on that you can find online, you can start with newton's method
Newton Raphson thing
Idk, to me the most straightforward way is just to enumerate the ways to make 5, 6, 7, and divide that by the total possible rolls
you should open a new channel (read #❓how-to-get-help) though
Might be nCr in disguise but it's really easy here
I need to know how to do this sort of thing in under 90 secs in about 58 days
Is this one of the harder cases of ncr
Cause I lowk have no idea how to do it with ncr
this is one of the cases where nCr is not necessary
I only know how to do ncr for the cases like question 18
I don't know how to use nCr here that isn't just for trivial computations
So I shouldn’t worry about it if I can’t figure out how to do it
?
With ncr
I just thought that might cut down the time for me
it wont when the method to do this is extremely quick
are you familiar with
2 3 4 5 6 7
3 4 5 6 7 8
4 5 6 7 8 9
5 6 7 8 9 10
6 7 8 9 10 11
7 8 9 10 11 12
Probably just get used to visualizing things like that table
Yh
(1, 2, 3, 4, 5, or 6) + (1, 2, 3, 4, 5, or 6)
Oh so I literally count?
Fairs
so its (6 + 5 + 4) / 36
How do I decide what’s n and what’s r in general
Very slightly different way to do it is to realize that you can make 5 with 1+4 and 2+3 and so on until you get to 4+1, which is obviously 4 ways; similarly you can make 6 in 5 ways, and 7 in 6 ways
No real need for the table but it's a nice visualization
Thank you
But say in another general situation when ncr is required
What’s a method to figure out what I use for n and r?
I don't think there's really a method, you just need to think about it the right way
Visualizing helps a lot
Have you done questions 20 and 21?
No
Aren’t they relatively simple probability questions?
Just feel the need to clarify I didn’t take 20 mins to do them 🤣
Well, yeah they are simple
I might need to out in some ncr practise
And probs a lot of thing I need to review and find more efficient ways to do
27 questions in 40 mins I think
But these questions are from the simplest part
I could’ve technically used ncr to figure out the 2 I multiply by if I wanted to complicate my life right?
Yeah
Is it 2C1
I assume cause red and green so 2
But I don’t fully understand why it’s 2C1
Bruh why can’t I just do pure
What’s wrong with differential equations
50million distributions pmo bruh
What’s the negative binomial gonna be useful for
Well for question 20 you can just split the experience: have 2 identical bags of balls, pull one from the first and one from the second, but the order doesn't matter so you have twice as many ways to do it
Oh right
It’s like how sets you have and how many elements you choose from each set?
No it's which set you consider first
If the two bags are labeled A and B, you have a choice between pulling from bag A first or from bag B first
(that's if you want to pull the red ball first; equivalently you can have the choice of pulling the red ball first or the green ball first, doesn't matter from which bag)
In nCr? n would be 2 because two sets, r would be 1 because you're choosing one
Wait if it’s the same bag and there’s replacement then surely there’s not an option?
Okay that might be more confusing than I wanted
If you consider just one bag, with replacement, then your choice is between picking a red ball first and picking a green ball first
Yeah but that wouldn't satisfy the goal
Oh it’s possible ways to do what we want
Yes
So like we take from the bag twice so like 2
Acc nah
Wait
I’m confused again 😭
Did this too long ago
Is it 2 because 2 selections?
Just imagine doing it IRL; in scenarios where you've picked a red ball and a green ball, then it's either because you've picked a red ball first and a green ball second or because you've picked a green ball first and a red ball second
Yes
Maybe I should think about this with a more complex situation
Maybe I’m getting confused cause it’s obvious there’s 2 ways to arrange 2 things
Yeah maybe
@ruby oriole Has your question been resolved?
Closed by @ruby 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.
can someone help on this pls ?
What have u tried
there's usually 3 ways to solve it
anyways yeah what have you tried
moving the -3 to the other side
completing the square
quadratic formula
factoring
Wont help
that doesn't really help
why ?
I prefer this over all
yeah factoring is the quickest
Cuz it's quadratic and all ig(what's the right answer to this question)
Do u k middle term splitting? @gray patrol
completing the square is a good idea too
Yea
the quadratic you've given can be factored though
Yea
so just by trying x = 1.5
And going through completing square can lengthen the process in this one
but is it ok to the doctor if i do it on that way ?
completing the square or factoring?
completing the square
U mean?
Probably, but you can do it quicker with just factoring
i was trying the numbers and i x = 1.5
here
But y
do you know how to factor?
so it is ok if i, said to the doctor the answer for it it is just 1.5, and not steps included
no sorry
U dont need to apologize 🥲
Well u wont be given the answer usually
there's also another answer
quadratics require two solutions
(if both the roots are real and it's not a repeated root)
so how can we do it by factoring
It can have 1 too if it's a perfect square(ryt?)
yeah I forgot to mention that
Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now: https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratics-solve-factoring/v/example-1-solving-a-quadratic-equation-by-factoring
Practice this lesson yourself on KhanAcademy.org right now:
...
Watch this if u can
i will thx alot <3
Np
@gray patrol Has your question been resolved?
The way I do it is multiply the first and last term
So -18
And find 2 numbers that multiply to this and add to the middle one
Once you find the 2 numbers
You get 2 brackets
(6x+a)(6x+b)
Then simplify the terms
So if 3x+6 then cancel it down to x+2
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.
hello
find ABC
one sec
alrrrrrrrrrr
180*(n-2)
no
.
n is the number of sides
abc is the angle u need
yes
alr
see what to do now?
look at ∆ABC
mhm
ab and dc are sides of a pentagon
yes
what is the difference between a regular pentagon and irregular
right
diffrent
now look at AB and BC
yes
thx <3
what can you tell about the ∆abc
they are
xd
you can now find acd
Closed by @slow oak
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.
help
No need to ask “Can I ask…?” or “Does anyone know about…?”—it’s faster for everyone if you just ask your question! See https://dontasktoask.com/

gay
so i have a prob
solve the equation $$log_8 x\-4log_8 x = 2$$
Communist Africa
what do you get if you turn $2=\log_8$ ...fill in the blank in the log
MichaelRafto
i suggest you just subtract the 2 logs on the left, then turn 2 into a $\log_8$
MichaelRafto
hm
huh ???????????????????\
if you do these, then what do you get?
that's not the question
yeah it's part of solving it
you want to solve $$log_8 x\ -4\log_8 x = 2$$, right?
2 = log_8
MichaelRafto
na this $$log_8 x\-4log_8 x = 2$$
huh alr
Communist Africa
that is what i wrote
ye
Communist Africa
?
using double dollar signs puts equations on their own line btw
what do i even do
how did you get $log_8 x/x=2$?
MichaelRafto
what do you have as of now?
just the question itself
so we are on square one
yep
what do you get if you subtract the logs on the left?
i'll get log_ x/x^4
no i mean without using any log laws just subtraction
no need for log laws yet
hm
you have $log_8 x - 4log_8 x$ right?
MichaelRafto
MichaelRafto
Communist Africa
and also when were done, i'll like to ask u something
right side wrong man
????????????????????
remember $1=log_8 8$
MichaelRafto
yea
if you have a smaller value than 8 in the log you get a result smaller than 1
$0.5=log_8 sqrt(8)$
MichaelRafto
explain it again
$0.5=log_8 sqrt8$
because inorder to reduce a decimal to its lowest form we use -whole nu,ber
ok
half
ok
(cmonnnnnn texit)
just like how $$1 = log_8 8$$
ye
so for 2 what do you have?
i have root 2
for 0.5
Communist Africa
the left hand you just subtract
it's like have x-4x
simple subtraction, no log laws required
oh
no log laws required
$$-3log_8 x$$
Communist Africa
= 2
then since 2 = log 2 2^2
why did you take $log_2$?
MichaelRafto
you can take $log_a$ with a being anything you want it to be
MichaelRafto
but in this exercise what do you want it to be?
8
so you take $log_8$
MichaelRafto
now there is one part in the log8 that is missing
yea
the number
wait
the RHS is 2
and we wanna log it
so inorder to log an unlogged
we have to make th base exactly the same as the other or in the left hand side
right
yes for $1=log_8$ tis $1=log_8 8^1$
for $1=log_2 its $1=log_2 2^1$
MichaelRafto
so $$2=log_8 8^2$$
Communist Africa
since $$-3log_8 x = log_8 8^2$$
Communist Africa
so im gonna cancel out the $$log _8$$
Communist Africa
ye
so its $$-3*x=8^2$$
Communist Africa
yea you have to divide with -3 before you delog (and you don't have to turn 2 into a log)
8 is not divisible by 3
$-3log_8 x=2$
MichaelRafto
$log_8 x= -2/3$
MichaelRafto
Communist Africa
that's 0.25
correct
and one more question
sure
i have trouble in math
and i wanna know ur secret
in learning knowing math so well
and how to become a pro
God tier Pro
without forgetting
im not that much of a pro man i just made a mistake earlier 😅
remember the methodology, save it somewhere
methodology, whats this
how you solve each exercise
i.e. remember the log laws same them somewhere and practice until you learn them by heart
imma try next question
cause when you forget the methodology you get stuck on the same things and it is tiring
alr
bye
.close
Closed by @mild cipher
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.
help
Communist Africa
so i tried using elimination method but didn't work out
can't understand ur tex writing
hello
R these two equations?
They r asking u to find out x and y?
Alr name the equations
1st one is eqn 1 and 2nd one eqn 2
but we were thought to use elimination becaue its short and simple
Alr so the intention of elimination is to eliminate a term with either x or y to find the value of one of them
Alr i'll let u choose which one i want to eliminate
Lol alr
So in order to eliminate x ,we have to ensure that the amount of terms of x is same in both eqn
While u do it ,u have to check if thee coeffecients of the x terms r same in hoth eqn or not
nope they're
If they r u dont need to do anything and straight up subtract(if both x terms r positive) and add(if they r negative)
Yes so we need to do configuration
Now u need to check which of the x terms has higher coeffecient
eq 1
And wht is it
$3log_3 y$
Communist Africa
Wait we r talking abt x
oh
U said u wanted to eliminate x ,no?
Alr so tell me the coeffecients of x terms both eqn
Communist Africa
$6log_5 x$
Communist Africa
when were done i'll like to ask u a question
Which one is larger
this one
Yes so can u multiply something with the smaller one to get the larger one
well
(When u notice they r divisible,u can definitely do that )
(But if they r not u will have to multiply both equation with each others' coeffecients)
im suppose to multiply 6 with eq 1 then 2 with eq 2
hm
yea
So u should multiply 2 with 5 amd 5 with 2
yea
But when it is 2,6 multiply 2 with 3 gives u 6 ,u dont need to do anything with 6
So do we agrèe to this
Alright
So if u multiply eqn 1 with 3 we get 2×3=6 as coeffecient of x term
Am i wrong?
so its not a must we do 2*6
Yes
just by multipling it once
Fiest show me the eqn
Remember to multiply the whole eqn
Not js the x term btw
here''
No i meant after multiplying
oh
wait what abt 6
math ehn\
one day i will become better et it
i wont need any bodies help one da
just make math i'll surpass u
Sorry phone had shut down on me
What
Sure keep it up
I mean u hv to multiply eqn 1 with 3 to get something to eliminate
alr
Multiply the eqn 1 by 3 and show me
Hm?
Oh yes multiply the whole eqn 1 with 3
Lhs and rhs included
Show me once u r done
There should be a plus
And u didnt multiply the rhs with 3
8 needs to be multiplied as well
wait
Communist Africa
alr
When u deduct u deduct both lhs amd rhs btw
When u subtract it wouldnt be
oh
Like 9 log3(y)-(-2log3(y))
like from
$$6log_5 x -2log_3 y = 24$$
Communist Africa
U can do tht
alr
But subtracting this from other one would be easier
Communist Africa
my answer
wait were exchanging it
There is a log btw
so it will -22 = - 11_3 y
wait
y tho
Like i said u can do both
ok
This would be the result of the other alternative
That's fine
Communist Africa
Yes
Log3(y)=2×1
Now express that 1 as a logarithm of base 3
(Man gottta be quick,my time is running out)
Communist Africa
So log3(y)=2×1
I termed it wrong
1 should be expressed as logarith of base of 3
Not 2
as i said
how
Getting to that(let's be quick)
ok
yea
Now 2log3(3)=log3(3)²
Taking the coefficient to power
Now eliminate log3
What do u get
@mild cipher
3²=6??
i did
3²=3×3=??
y = 2 * 1
y = 2log_3 3
y = 2 * 3
y = 6
log₃(3) ≠ 3
Please use LaTeX if you can
do you mean $2\log_3(3)$?
EightyEightEpsilons
Because in that case it would be 2•1, in which that would equal 1
Uh when u eliminate log ensure that they dont have coeffecients before log
log _3 y = 2log_3 3
We made 2×1=2log3(3) cuz that's what we needed
Huh?
Ig he'll take over
like that log_3 cancel the log_3 remaining 3
Does 𝑦 = 3² or something?
That’s not correct
$2\log_3(3)=2$, because $\log_{x}(x)=1$, for all $x>1$
EightyEightEpsilons
$2\log_3(3) \ =2\cdot1 \ =2$
EightyEightEpsilons
understand?
yea
is there something I’m missing?
The main question
Yall r basically heading back to the question
I’m doing my best with what I’ve got — I only come here because I stumbled upon something that was wrong
Log3(y)=2log3(3)
Make him realize why y=3²
Okay
Ik ik ,thanks for taking over,igtg
Sorry if it came out as something rude,i didnt mean it that way
$\log_a\left(b^c\right)\Longrightarrow c\log_a(b)$
EightyEightEpsilons
like i did $$log_3 y = 2;
log_3 y + 21;
log_3 y = 2log_3 3;
cancel log_3;
y=23;
y=6;$$
We’re assuming 𝑦 = 3² correct?
Communist Africa
im showing how y = 6;
hm
it’s 9
uhh no
EightyEightEpsilons
wait
No it’s 9
the square cancels square
I wrote the math wrong
how
your not suppposed to do a square root at all
EightyEightEpsilons
thxs guys
Use .close once you have figured everything out
Closed by @mild cipher
Use .reopen if this was a mistake.
.reopen
✅
what