#help-27
1 messages · Page 393 of 1
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
back
like pi-x and adding both integrals?
\begin{align*}
I &= \int_{0}^{\pi}x^{3}\ln\left(\sin\left(x\right)\right)dx \
&= \int_{0}^{\pi}\left(\pi-x\right)^{3}\ln\left(\sin\left(x\right)\right)dx \
&= \int_{0}^{\pi}\left(\pi^{3}+3x^{2}\pi-3x\pi^{2}-x^{3}\right)\ln\left(\sin\left(x\right)\right)dx \
&= \frac{1}{2}\int_{0}^{\pi}\left(\pi^{3}+3x^{2}\pi-3x\pi^{2}\right)\ln\left(\sin\left(x\right)\right)dx\
&= \frac{1}{2}\int_{0}^{\pi}\left(\pi^{3}\right)\ln\left(\sin\left(x\right)\right)dx+\frac{1}{2}\int_{0}^{\pi}\left(3x^{2}\pi\right)\ln\left(\sin\left(x\right)\right)dx-\frac{1}{2}\int_{0}^{\pi}\left(3x\pi^{2}\right)\ln\left(\sin\left(x\right)\right)dx \
\end{align*}
Roy
Then I guess they used the results $-\frac{\pi^{2}}{2}\ln\left(2\right)=\int_{0}^{\pi}x\ln\left(\sin\left(x\right)\right)dx$ and $\int_{0}^{\pi}\ln\left(\sin\left(x\right)\right)dx=-\pi\ln\left(2\right)$
Roy
So $$I = \frac{3\pi}{2}\int_{0}^{\pi}x^{2}\ln\left(\sin\left(x\right)\right)dx+\frac{\pi^{4}}{4}\ln\left(2\right)$$
$$= \frac{3\pi}{2}\int_{0}^{\pi}x^{2}\ln\left(\sin\left(x\right)\right)dx+\frac{3\pi}{2}\int_{0}^{\pi}x^{2}\ln\left(\sqrt{2}\right)dx$$
Roy
Which is a pretty neat way to force out a factor of the denominator once you combine them with log laws
You can derive these two with repeated applications of kings rule and symmetry
Or with fourier series
Closed by @glossy dew
Use .reopen if this was a mistake.
Yeah their working of it is not very nice
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 can someone help me with question 2e and 2f please
what have you done so far?
this is what i have done for e
but idk am i in the right track or not
just looking at the start, you've differentiated sinx correctly but the xsin(2x) term requires the product rule
you have two functions in x so we need to use $\frac{d}{dx}uv = u'v + v'u$
melon
can you redo the differentiation of xsin(2x) ?
correct
oh and the derivative of sin(2x) is 2xcos(2x) right
Same thing
as stated already, when we differentiate sin we need to chuck the derivative of the insides to the outside
more formally $\frac{d}{dx}\sin{(f(x))} = f'(x) \cos{(f(x))}$
melon
then i will use this as a gradient for the tangent
then i will find the equation using y - y1 = m(x-x1) right
Yes
yes very good
Closed by @quaint valley
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Someone Help me prove this
@unique canyon Has your question been resolved?
<@&286206848099549185>
do u know what lcm*gcd=
Product of numbers?
It looks really weird to me, isn't n a common multiple of a_i ?
since gcd(ai,bi)=1 , k_i/b_i should be an integer, or I am being dumb here
@unique canyon Has your question been resolved?
Why do you say
uh say what
n is rational =aiki/bi so ki= nbi/ai, since bi and ai are coprime ai|n
as ki is natural number
n is natural number
n belongs to q+
What
Okay lmao it say i=1,2,...,n so I assumed n is integer
But smth like a_{1/2} is weird as hell
.close
Closed by @unique canyon
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 me with this please
do you know log laws
@quaint valley 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 books that
Keep in mind that my teacher doesn’t use the unit circle much btw yall
Pre calculus with limits 8e graphing approach
dam
sin( pi -t) = sin t , sin (pi +t) = -sin t , cos(pi-t)=cos(pi+t) = -cos t
both
-sin t
unit circle
Does this have anything to do with parallel lines intersected by a line
That’s what a teacher told me
Grab any point on the unit circle. Rotate it 180 degrees or π radians around the origin. Notice that its y-value is the negative of its original y-value as it's been reflected about the origin.
I'd recommend you watch a video on that, then
it defines trig girl
trg starts from unit circle
No like what are the points of a unit circle
Is it the thing they tell us to memorize
My teacher told me not to memorize that 💔
He rlly said “we ain’t doing that in this math class”
The unit circle gives a great intuition for trigonometric functions
i think its right
Oh okay
thats the unit circle, but the one thats useful is this one
Wait i still don’t understand why sin (pi - t) = sin t
What the 😭😭
try to plot the angle t and the angles pi+t and pi-t using this
Bro I think I’m gonna go to sleep and just ask my teacher tmrrw 😭
lol
ehh, its pretty simple tbf
kinda
you got a circle, and you mark an angle on it
Bc it’s super late and not worth it atm, I’ll just go over it tmrrw when I have more time
Wait no I see what that image is showing lowkey
then the x coordinate is cos and y one is sine
I see it now
and you gotta then track the angles and sides for those various configurations asked in your problem
Closed by @wise violet
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Hai..
Can someone help me how to solve...
-
Probability equation, Union And Intersection, and the dice probability thing: 1/4 + 1/4 - 1/4 = 1/4
-
Distance formula
-
Permutation and Combination
-
General form
What?
@paper dawn Has your question been resolved?
Wait
P(AUB) = P(A) + P(B) - P(A (upside down U) B)
So it's the probability of one or the other happening, but not both
That is, if events A and B can happen at the same time, we need to account for that
Probability of A and B both happening is just probability of A multiplied by probability of B
So if P(A) = a, P(B) = b
P(A and B) = a*b
@paper dawn Has your question been resolved?
Closed by @paper dawn
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
, rotate
oh thanks
So consider this
If I want to choose someone for the first position, how many ways to do that are there?
You have 15 people
So there are exactly 15 ways to choose the first player of the team
15^10?
No
or 10^15?
If you chose someone for the first spot, how many players unchosen are there?
Not at all
Again
Think about it logically
Forget the math
You have 15 players for the first spot in the team
first position we can get is 15, then 14 ,then 13?
Yes!!!
13 for the third
so half knowledge is bad
15
14
13
12
11
10
9
8
7
6
And at each step there's a branch
So we need to multiply
Makes sense?
15 * 14 * ... * 6
For each of the first 15 picks you can choose 14 picks in the second spot for which you have 13 picks in third and so on
k
It's called the number of permutations
Permutations are ordered. That means it matters whether John is in the first or 10th spot
But in our case we only care whether John is in the team or not
Doesn't matter which spot
So we essentially just overcounted
is this an example?
So if team is (player 1, John, etc) it's different from (John, player 1, etc) in this case
k
k
How many ways are there for 10 team members to be in the team?
Again, 10 for the first spot, 9 for the second, etc, 1 for the last one
oh
why 10 tho
Because there are 10 spots for the team members
wait I'll try and example
Imagine you have 10 people. How many ways are there to arrange them? It's 10 * 9 * 8 * 7 * 6 * 5 * 3 * 2 * 1
This is called 10 factorial
10!
Okay. So that's the factor by which we overcounted
We have 15 * 14 * 13 * 12 * 11 * 10 * 9 * 8 * 7 * 6 permutations
If we don't care about the order, we must divide this by 10!
one sec
We get what's called combinations
Combinations don't care about order
so we get 12 possible outcomes when position doesn't matter. and we have 4 players and 3 slots
no I'm wrong
we get 4
when position doesn't matter
and 24 when we count position
so 4!/3!
4* 3* 2/4*2
not counting 1
in this case we get 15!/10!
?
First 10 terms of 15!
15!-5!?
Not minus, divided by
And then we divide that by 10!
Yes. Because again, 15!/5! is permutations
That means it matters how players are chosen, in which order
1 2 3 4 5 6 7 8 9 10 is not the same as 1 3 2 4 6 5 7 9 8 10
yea
But we don't care about that
permutations are the total positions counting the place?
Because the same 10 players in different order is the same team
got it
So we want to exclude the number of ways in which we can order 10 players in the team
how will we calculate the probability that player one is in position 6
so 15 is the number of players=N
10 is the number of slots or position which =M
the formula will be N!/M!*(N-M)!
Yes!!!!!
ooooo
You're a genius
no
i am dumb
people my age are learning this
and I don't even know the chapter's name
btw when we learn this
and how will we calculate the probability that "John" is in position 6 when position matters
@winged hearth Has your question been resolved?
which question are we on?
umm not the question
idk permutation and combination
so I am trying to solve but I am learning
i don't like textbooks
they don't make me understand
ok, what do you know ?
you are referring to nPr = something and nCr
permutation is arrangement
where as combinations is choosing different set of things
eg you have 9 people and you have to seat them at 9 seats in a row, the total number of ways you can seat them is permutation
yea
ik that
why do you have undergraduate role ?
yea
rn
if there r 15 options
10 slots
and John a player has to be there
in 1 of the 10 slots
ok, how many players
15
total
what is the probability that John is in 6th position out of 10
so you have 15 players to be seated in 10 seats and find probability jon is in 6th spot ?
right ?
@winged hearth
yea
btw a question first
is this hard or the probability question
, rotate
Closed due to timeout
Use .reopen if this was a mistake.
.reopen
✅ Original question: #help-27 message
@round raptor
wher is probability question
ik
what maths wise what will be harder
i want to go for easy ones
to get my basics clear
this
harder or easier
not harder this will help in thinking your question and that, i would say both easy but that better
tbh you should not focus on difficulty rn
do both
i mean if I am doing a hard question at the start without knowing what I'm doing then no point ig
yea I meant first that
right
ok
so first this ?
yea
what do you think for a) 1)
no restriction means the same people again in different positions or positions doesn't matter
hey I have a math qsn can i post it here?
!occupied
Someone else is already using this help channel. If you need help with a question, please open your own help channel/thread (see #❓how-to-get-help for instructions).
alr
bt different i think position doesn't matter
by*
so it means no matter John is number 1 or 2
?
no restriction means we can do operations normal way
what do we mean by normal
so combination?
so does not matter you choose jon first or last the team formed will be same 10 people
yes
shoul I use calc
eg if they applied restriction that they want john and tom in every team then we need to choose john and tom everytime , every team will have them but other 8 members will change
no, for small numbers
is 15! small. idk first time working with factorials for a question
so you have to make team of 10, so choose 10 out of 15
no, but it will cancel out with denominator
k
yes
so after manual calculation I am getting 3 7 13 * 11
that's some work
right
yea it's 3003
yes
?
no
where are 3 same ?
this
oh that is next part
applying restrictions
so, 3 sisters are always selected
oh shit
i thought that 3 sisters part is for 1a
mb
k
i think the answer will be very big
it is but there two parts for 1
for?
now you know 3 always selecte
for the pinned qsn
a 1?
calc is allowed
this one
yea
alr
you have to select remaining 7
yes
but there will be 12 people to select from
you know the ans arsh?
k
its coming out to be 19508428800
💀
dw we'll see if its big we will leave it without calculating
lmao no way
not possible
alr maybe i did some mistake
right
yes
,calc 1198
Result:
792
huh
answer key says 858
uh then?
if you select none of3 then they would not be separated
so you need to make cases where you always select them and you select none of them
and the cases
pnc is like that
correct
792+66
right
yaaaaaaay
that would be 858
yeye
, rotate
last place should be 0,2,4,6,8
0 is not an option for the first place
we find permutation for all conditions
- when 0 is 1st place(idk how
then - when 0,2,4,6,8 is not the last place
divide in two cases where 0 is in last place and it is not
0 can't be in 1st
we - the answer from the main thing
case 1 0 is in last place
oh
ok
so consider you can place 0 in first place
how many ways can you arrange them all
so idk how
right
we consider 0
so 10
2nd digit
ah wait
ig
k
so how many ways for last digit
5 of the numbers can be in the last place
yes
now let's fill others
how many ways
huh
the* gets formatted
you have filled 2 digits with 2 numbers how many remain
10-2
so 9 can be 1st place bcz 0 is not there so we have 9 numbers technically for 1st place but we have 10
but when we go to 2nd position we have that 0 so it is 9?
we consider 0 at first place
your method
right
but this isn't including that last is even
this is when first place is 0 or not zero
how ?
it is 0
10 total possible outcomes
but only 6 can be used
we include both cases where first place canbe 0 and not, now subtract where 1st place is0
?
the normal formula
no, we have to put even number as last digit
.
subtract cases where 0 is in 1st place
other way aroun
?
can not be 0- can be 0
no
you said we - arrangements where 0 is in 1st place
so we consider we can place 0 in first place and calculated arrangemets
5numbers of last digt
then 9 for 1st, here if we put 2 as last digit
then 0....2 and 1...0...2 is also possible so this contains both cases where 0 is in 1st place and not
so we just subtract the cases where 0 comes 1st like 013542
yea that's what I said ig
so 102746-023138
eg
ok, instead of cannot you should write can and cannot
oh yea my bad
so, how many arrangements with 0 at first
i was thinking this and wrote that that's y I lose marks

i feel you
75600
,calc 87654
Result:
6720
hm..
what did you do?
98765*5
ok
and for this
151200
you are rght but that is total arrangements
what did you do?
oooooo my god
i am so dumb
109876*5
mm.. no
put 0 in first place, 1st digit fixed
now last digit
how many numbers can you put ? (2,4,6,8)
this is for when it is 0 and even?
right
now you have fixed two numbers 0 at first and even at last
how many ways can you fill other 4 slots
so out of 4 even we used 1 we have 3 remaining and we have 1 removed already (0)
so 8 numbers can be in the remaining 4 slots
8
yes
so how many ways?
so this
- this
yay
6720
turned out to be harder this way
right
oh
but we reached
waah
igcse so doesn't matter
u r in?
11 th
college?
yeah school
yeah
which ones
engineering
jee?
yes
If you are done with this channel, please mark your problem as solved by typing .close
.close
Closed by @winged hearth
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 with the d) so
are you sure u should interpret it as x <= 92?
oops
shouldnt it be just x <= 93 (since height is "continuous")
yeah, but its quite unlikely that anyone has exactly 93cm
you already have to count 92.9999999999999999cm people
x <= 92cm doesnt count those
x <= 93cm is practically the same as x < 93cm if x is distributed among reals
hmm okay
yeah its confusing cuz it says less than
ohhh
i get what u mean now
shits confusing
it makes more sense that way, because now 93 and 113 are same distance from the mean
hmmm
so u can do it even more simply by 2*p(x<=93) (by symmetry of the bell curve)
yeah
also what do u refer to
like lets say ur doing normal distribution but a height unit or something
you dont have a p then right
a probability
wdym?
here's what i meant btw, both 113 and 93 are 10 units from mean, so the areas of the tails are gonna be the same, due to symmetry
so, you see the 2500 parts, theyre different from when you use a discrete probability
you cant call them p
are u asking how to refer to the parts?
maybe just call x the number of scrap parts produced, then its asking about p(x=0)
yes yes
okay so
i already did that i need help on another thing
wait
oh wait btw
its "r“
i saw
what is r?
the 2500 parts
like
if i would use the fi function
r - mu / sigma
is the Z value
if im not allowed to use a calculator
the integral?
this stuff
i guess yeah
this is another exercise tho
yeah, so whats ur question?
Are u asking about what r should be here? (in the machine parts Q)
i dont see d
i just have to like
oops
i mena c
c)
uhhh
yeah wtf do i do there 😭
is it something with the deviation
I'd figure out the real probabilities
so 2% of 18 and 10% of 18
whats the probability that a vehicle is between 2% below and 10% above the mean?
omg
its like
wait
p(mu-2% of the consumption <= x <= mu + 10% of the consumption)
?
holy shit
and the salesman claims that that probability is at least 50%
so if the probability isnt above or 50 then its wrong
but wait why is <= x < = correct
"...deviate from the standard fuel consumption by a maximum of 2% below and 10% above"
oh
yes
can i keep this channel open ? im studying rn and i get stuck sometimes
hmm actually it might be better if u open a new one every time
ill probably not be able to respond soon and opening a new channel will bring u more attention
okay ty
@neon wagon Has your question been resolved?
Closed by @neon wagon
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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! I need help with letter (b).
you need help with b) of problem 3.23 or 3.24?
for 3.24, it helps to remember that cosine is the ratio of the adjacent and the hypotenuse of a right triangle
so, for a ratio to be positive, the numerator and denominator BOTH have to be positive or negative
now, since the hypotenuse is always positive, the adjacent must also be positive, which means that angle v points in a direction where the horizontal (x) axis is greater than 0
@coral forum Has your question been resolved?
Ohh problem 2.34
@coral forum Has your question been resolved?
you mean 3.24?
we know a few things about sin(90°), cos(90°), and cos(v) on their own, right?
is there an identity that would "split" (90° - v) into ratios of 90° and v, by themselves?
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Divide −4𝑥^2+6𝑥 by 3𝑥
When dividing algebraic expressions, we can write the division as,
−4𝑥^2 + 6𝑥 / 3𝑥 or (−4𝑥^2+ 6𝑥) ÷ (3𝑥)
We use the fact that division is the same as multiplication by the mutiplicative inverse:
(−4𝑥^2 + 6𝑥) * 1/3𝑥
And now we use the distributive property to evaluate the expression,
−4𝑥^2 /3𝑥 + 6𝑥/3𝑥 = −4/3𝑥 +2
Why does the reciprocal matter here?
aren't we just dividing each one by 3x? I don't see any multiplication in the distributive property
tbh it doesnt really matter
its just another way to write it
in the reals and rationals
Division is literally multiplication by the inverse
the first term should be written as -4x/3 instead of -4/3x
oh yeah, didnt see
maybe it's helpful to latex the fractions so where the x is is unambiguous
$6x\cdot \frac{1}{3x} = \frac{6x}{3x} = 2$
ahh I need to familiarize myself with latex
@marble hearth Has your question been resolved?
Closed by @marble hearth
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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
To ask for mathematics help on this server, please open your own help channel or help thread. See #❓how-to-get-help for instructions.
that should probably be different if you open a thread with it
anyways this is the right place, post your question and people will see it and hopefully help
@woven haven Has your question been resolved?
@woven haven Has your question been resolved?
.close
Closed by @woven haven
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 pls check if I did this right? I’m in AP Precalc and we’re working on trig functions for this chapter
For the work above, I ignored the 9 degree angle bc I didnt see a use for it. Pls lmk if I’m wrong
that's a sign that you might be doing smth wrong
And yah it's wrong
Nvm I did it wrong
I don’t have the full base length oops
Gimme a moment to figure this out 😭👍
Lowk dunno how to do it
😭
I redrew the diagram tho
Hopefully this is at least right
yes
you should be able to relate d and the whole base length to h right?
Oh
similar to what you did here
Tan of both angles
And then rearrange so both equal to h
Then set them equal to each other?
yeah
or you rearrange them so both equal to d, so you can find h directly
this's right, I think, after you get d you can compute h
looks good to me
Idk how to isolate h 😭😭😭
Oh subtract 3h from both sides
well, 1/tan(3.5) is just a number
approximately 2.6696
you can just do the same thing here
factor out the h
Oh
I keep forgetting that I can factor in situations like this 😭
Yay
How come I can’t do this btw
In the box
Instead of dividing -13 by a fraction, I flip the fractions in the denominator? It doesn’t work tho and idk why
$\frac{1}{\tan(9^\circ)}-\frac{1}{\tan(3.5^\circ)}$ is not A fraction
Alexis_Fx <- sucks at Math
There're 2 fractions
If we make them a single fraction
$\frac{1}{\tan(9^\circ)}-\frac{1}{\tan(3.5^\circ)}=\frac{\tan(3.5^\circ)-\tan(9^\circ)}{\tan(9^\circ)\tan(3.5^\circ)}$

Alexis_Fx <- sucks at Math
then can flip the rhs
np
Closed by @wise violet
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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 tried to square it then subtract by 4b both sides to try and get a workable eq but i didnt
i honestly dont have any clue how to solve with powers when u cant simplify it
is this a multiple-correct question?
yea
$a^2 - b = (a+ \sqrt{b})(a-\sqrt{b})$
Annie Maqionde
This doesn't even make sense. Roots in which variable?
x
what do u mean?
it does make sense
mb a and b are constants'
Oh I see
take $y = (a+\sqrt{b})^{x^2-15}$ and its a quadratic in y
Annie Maqionde
how would i express a - root b?
in terms of y
uhh
1/y
mb 😭
so
im getting the roots of the quadratic in y as (a + rootb) and (a - rootb)
so from that
im getting options 1 and 3
correct
Closed by @wanton tiger
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
odieee
there's no asymptotes
Hi beeeeeam!!!! 🤗 ❤️
Wait so its wrong?
yeah, cause for x < -1, f(x) exactly equals -2
and for x > 1 f(x) exactly equals 2
yep
yeah
Closed by @viral lynx
Use .reopen if this was a mistake.
no worries!
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Given a, b, c > 0 so that a+b+c=3, find min of $\frac{a^2+67}{a+1} + \frac{b^2+67}{b+1} + \frac{c^2+67}{c+1}$
Thomas
I think that we can transform it to $a - 1 + b - 1 + c -1 + 68*(\frac{1}{a+1} + \frac{1}{b+1} + \frac{1}{c+1}) \rightarrow 68*(\frac{1}{a+1} + \frac{1}{b+1} + \frac{1}{c+1})$
Thomas
yes i just did it
which means that we only need to find min of $\frac{1}{a+1} + \frac{1}{b+1} + \frac{1}{c+1}$
Thomas
Titu's Lemma should be able to do this
which gives 68*3/2 = 102
so that should be it
can anyone send q query to draw this out?
thats correct
onto the next question in the practice test that i have problems with: geometry
Given two circles (O) and (O') with equal radius R. Draw O'A as a tangent to (O), and draw OB as a tangent to (O'). On the ray opposite to AB and BA, respectively, take points C and D such that AC = BD. Construct the rectangle EFCD whose length is greater than 4R. Draw (I) with diameter EF. Choose point L on (I) such that triangle ELF is an isosceles right triangle with the right angle at L. Draw EH and EN as tangents from point E to (O); draw EK and EM as tangents from point E to (O') (with N lying inside (O'), and M lying inside (O).
Prove that HMNK is an isosceles trapezoid.
Diagram please
Wait
am redrawing it on geogebra
my original one looks 3x more confusing just from the scrub marks alone
@sand girder Has your question been resolved?
What part are you stuck
That so much going on
I kinda need help w this: "draw EK and EM as tangents from point E to (O') (with N lying inside (O'), and M lying inside (O)" (original ques but i don't know how to draw that so i just let N inside (O) and M inside (O'))
I think you got confused here it should be " (with N lying inside (O), and M lying inside (O')."
@sand girder Has your question been resolved?
but that doesn
't give me trapezoid
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Closed by @iron 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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
looking for a good book to practice math analysis from start
(proving axioms and then reals etc)
.close
Closed by @whole hornet
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
\begin{Theorem}
Assume $A$, $B$ and $C$ are sets. Then, \ $A \cap (B \cup C) = (A \cap B) \cup (A \cap C)$.
\end{Theorem}
\begin{proof}
Let $A$, $B$ and $C$ be sets.
First, we will proof that $A \cap (B \cup C) \subseteq (A \cap B) \cup (A \cap C)$.
Suppose that $$x \in A \cap (B \cup C).$$
Then, by the definition of the intersection, $$x \in A \text{ and } (x \in B \cup C).$$
And, by the definition of the union, $$x \in A \text{ and } (x \in B \text{ or } x \in C).$$
For this to be true, $x$ must be in $A$, and it can be either in $B$ or $C$.
Said differently, $$(x \in A \text{ and } x \in B) \text{ or } (x \in A \text{ and } x \in C).$$
Then, by the definition of the intersection, $$(x \in A \cap B) \text{ or } (x \in A \cap C).$$
And, by the definition of the union, $$x \in (A \cap B) \cup (A \cap C).$$
Since $x \in A \cap (B \cup C)$ implies $x \in (A \cap B) \cup (x \in A \cap C)$,
we have $$A \cap (B \cup C) \subseteq (A \cap B) \cup (A \cap C).$$
Next, we will proof that $(A \cap B) \cup (A \cap C) \subseteq A \cap (B \cup C)$.
Suppose that $$x \in (A \cap B) \cup (A \cap C).$$
By the definition of the union, $$x \in (A \cap B) \text{ or } (x \in A \cap C).$$
Then, by the definition of the intersection, $$(x \in A \text{ and } x \in B) \text{ or } (x \in A \text{ and } x \in C).$$
For this to be true, either $x$ is in $A$ and $B$, or in $A$ and $C$.
In both cases, $x$ must be in $A$, and then it can be either in $A$ or $B$.
Said differently, $$x \in A \text{ and } (x \in B \text{ or } x \in C).$$
Then, by the definition of the union, $$x \in A \text{ and } (x \in B \cup C).$$
And, by the definition of the intersection, $$x \in A \cap (B \cup C).$$
Since $x \in (A \cap B) \cup (x \in A \cap C)$ implies $x \in A \cap (B \cup C)$,
we have that $(A \cap B) \cup (A \cap C) \subseteq A \cap (B \cup C)$.
Therefore, $A \cap (B \cup C) = (A \cap B) \cup (A \cap C)$.
\end{proof}
Mor Bras
Hello, could someone check if this proof looks good please?
seems fine to me but im no expert
Yay! ...I guess?
oh u did misspell "and" in ur fourth last line
\begin{Theorem}
Assume $A$, $B$ and $C$ are sets. Then, \ $A \cap (B \cup C) = (A \cap B) \cup (A \cap C)$.
\end{Theorem}
\begin{proof}
Let $A$, $B$ and $C$ be sets.
First, we will proof that $A \cap (B \cup C) \subseteq (A \cap B) \cup (A \cap C)$.
Suppose that $$x \in A \cap (B \cup C).$$
Then, by the definition of the intersection, $$x \in A \text{ and } (x \in B \cup C).$$
And, by the definition of the union, $$x \in A \text{ and } (x \in B \text{ or } x \in C).$$
For this to be true, $x$ must be in $A$, and it can be either in $B$ or $C$.
Said differently, $$(x \in A \text{ and } x \in B) \text{ or } (x \in A \text{ and } x \in C).$$
Then, by the definition of the intersection, $$(x \in A \cap B) \text{ or } (x \in A \cap C).$$
And, by the definition of the union, $$x \in (A \cap B) \cup (A \cap C).$$
Since $x \in A \cap (B \cup C)$ implies $x \in (A \cap B) \cup (x \in A \cap C)$,
we have $$A \cap (B \cup C) \subseteq (A \cap B) \cup (A \cap C).$$
Next, we will proof that $(A \cap B) \cup (A \cap C) \subseteq A \cap (B \cup C)$.
Suppose that $$x \in (A \cap B) \cup (A \cap C).$$
By the definition of the union, $$x \in (A \cap B) \text{ or } (x \in A \cap C).$$
Then, by the definition of the intersection, $$(x \in A \text{ and } x \in B) \text{ or } (x \in A \text{ and } x \in C).$$
For this to be true, either $x$ is in $A$ and $B$, or in $A$ and $C$.
In both cases, $x$ must be in $A$, and then it can be either in $A$ or $B$.
Said differently, $$x \in A \text{ and } (x \in B \text{ or } x \in C).$$
Then, by the definition of the union, $$x \in A \text{ and } (x \in B \cup C).$$
And, by the definition of the intersection, $$x \in A \cap (B \cup C).$$
Since $x \in (A \cap B) \cup (x \in A \cap C)$ implies $x \in A \cap (B \cup C)$,
we have that $(A \cap B) \cup (A \cap C) \subseteq A \cap (B \cup C)$.
Therefore, $A \cap (B \cup C) = (A \cap B) \cup (A \cap C)$.
\end{proof}
Mor Bras
@raven kayak Has your question been resolved?
<@&286206848099549185> 👋
looks good to me!
are you an expert? 😆 (look earlier messages)
well, i did all these set theory problems 2 years ago :) but i dont think i'm an expert >.>
Closed by @raven kayak
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.
• Do not immediately ping people or roles. After 15 minutes, feel free to ping <@&286206848099549185> once.
• 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.
Not sure how to proceed. I was thinking of inverting the second fraction which would then be first fraction multiplying the second fraction but I don't think it will lead me any further...
Maybe firstly raise the powers and then do it
You'll be able to cancel out something and it'll become simpler
Ok brb
