#help-27
1 messages · Page 233 of 1
KySquared
!original
Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.
might require to know what f is
It’s not a problem I was given persay, I’m looking at Fourier transforms and was asked to verify why $\mathcal{F}{\frac{dx}{dt}} = -i\omega F(\omega)}$\
f is just an arbitrary function
KySquared
So the last part I need to show is $xe^{iwt} \eval_{\infty}^{\infty} = 0$
KySquared
I figured since e^iwt has magnitude 1, I only needed to consider x evaluated at those limits
And all I know about f is that $\abs{f(x)} \eval_{-\infty}^{\infty} =0$
KySquared
@sand dove
uh small problem
|f(x)| has no limits between +inf and -inf
unless you meant cauchy principal value
?
But f(x) is real. It should eventually die off
^
We are assuming f(x) has this pro- OHHHH
Even though f(x) has that property, that doesn’t tell us anything about f(x)

.close
Closed by @ember patrol
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 double check my work
looks all good!
Everything makes sense?
@humble sapphire Has your question been resolved?
@humble sapphire your hand writing is insanely neat
No it’s not
its actually neat LOL
The pencil is half broken
Can someone double check
I’m literally rushing lol
yup looks all good to me
Closed by @humble sapphire
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
i tried to solve this
by solving the integral from 0 to 3
and i got c = 1/21
however this is the solution
i dont understand why their method works (or why my method is wrong for that matter)
I mean, your problem is discrete
You use the axiom of probability to show that the sum is 1.
Your method is more on the line of determining the c if your input is from [0,3]
which has infinitely many elements
so your x (given your method) can be 1.3214 or 2.1124
i see, but are they not asking for a function here?
or what is the function they ask for?
I mean... they are asking for c. they already give you a function
that function is probability mass function
how is that connected to a random variable
it assign probability to the number defined by random variable
like you assign x = 0 with 4/30
but the values are from x not X
your random variable can be 0 with 4/30 probability
your x is realization value of X
realization?
like, you already know what it is (in terms of value)
like you can roll a dice. You can define your random variable from the face of the dice. I don't know what it is but once I roll it, I know the value
and I know that it will be 1 with probability of 1/6 and so on
but I don't know what it is yet in the form of random variable
ohh i see now. and it has to add up to 1 because 0 to 3 is all the possiblr values?
yes
Closed by @wild imp
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 know I have to use modulus
but I'm not sure how to execute this problem when subbing d into the second equation
Can anyone help me with this please
@storm current Has your question been resolved?
the property that if a|b, then a|b*k where k is an integer helps here
not sure i follow
if some integer is divisible by 3, then 2 times that integer is also divisible by 3
so if 2a + 4b + 3c + d is divisible by 5, any multiple of it is also divisible by 5
anyways if you get stuck someone just asked this in another channel
You can also multiply the first equation by three mod 5
.close
Closed by @storm 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.
If the tangent for the function f(x) = e^x at ( 0 , 1 ) intercepts both the x and y axis at point A, B
Then the area of triangle ABO where as O is the origin equals :
I'm having trouble visualising this
I want to send my try on this and please correct me lighty
Lightly*
Ik bad photo be patient with me 👏
What did I do wrong here
did you find the equation for the tangent line at (0, 1)?
Equals 1?
I'd first find the equation of the straight line containing the tangence point
Cuz e^x?
Then find the coordinates of A and B, draw the triangle and calculate the area using vectors
I know you're helping but please chill I'm trying to understand this not to just figure out the answer 😭🙏
Alright, sorry if I went a bit too fast there
You're fine 🙏
So first I need to find the tangent line using the point slope form? Or something else?
Well, the points A,B and (0,1) must be the in the same straight line, do you get why?
Yeah, that's what I'd do first, be it using the point slope form or any other
Because it intercepts both x and y?
OK wait wait I need to know something first
Can you visualise it for me on a graph? I know it won't be accurate because it has e but you can change that
Alright, brb
I'm just not getting how the function and tangent are drawn
Tysm 🙏
It's more purpleish but yeah
Yup
I would say indigo
Fair enough
You were asked about the area of the triangle OAB right?
Wait when it says it intercepts both x and y at A and B
But it also intercepts ( 0 , 1 ) no?
Yup, was about to tell you that
(0,1) is one of the vertices of the triangle, a straight line can only intersect each axis once throughout the entirety of its domain
Does that mean I have 3 points? First is 0 , 1, second is B, third is A
Is that correct?
Nope, that means (0,1) is either B or A
B and A are the points of intersection, each one for an axis
Then the third vertice of the triangle is the origin(as specifically stated by the problem)
The origin is always (0,0)
Probably
Generally denoted as O
Yeah okay got that when I remembered that 0 , 1 is either A or B
Then you need to calculate the last point and then find the area
Ok
Something like that Ig
But you still need B, and since you know it's the intersection with the x axis
You already know y=0
Bruh I changed location like 5 times doing this is why its taking so long mb 😭
OK so I plug 0 into y = x + 1
To get the point
Now that I have all points I can just do 1/2 * h * b ?
Okay got it
Wait do I
How is an area fucking negative
I'm lost
@brittle inlet sorry can you help or?
<@&286206848099549185> 😭
Let write my issue again cuz no one wants to read ik
.Close
Oh?
It's not closing
Divine sign
Shit I thought it was help 😭
Yes
feller was about to give up on us
Aight let me see
Nah just the guy who was helping stopped sending
I moved locations too much so I took long responding 😭, I don't blame him for not responding
the value of the area under the line is negative, but an area cannot be negative, if you get a negative area you'd subtract that part from the area
or something im sorry i really should have payed more attention in school
it is something like that though
you can have a negative area in the sense that it means you'd subtract that area from something
but like you say you can't have a negative area
The are of the triangle is negative ?
It came out negative for me
yeah well in this case you can use an absolute value
I😭😭😭
What did you do ?
Aight give me a second
if they ask for an area you need to take the absolute value
just turn any negative positive
and you will have your area
b*h/2
Yes that
h=1 and b =1
b is negative 1 no?
you could say that too yep but you'd have to turn it positive
If I can just do that then really I got it right
No matter the sign?
= 1
yeah when we talk about areas
Oh OK makes sense
they will always be positive except for very very few exceptions that come way way later on
if it would've integrated you could have gotten a "negative" area, but again you cant have a negative area so you just take the absolute value of that. if they wanted the value of the integral the answer would be negative
i think that's how it goes
sorry for not being able to express myself in solid math terminology
Closed by @tiny oyster
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.
yo i need some clarity on two equation formulas
yeah the first one
@summer sage Has your question been resolved?
Sorry, was busy
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.
hi I’m not sure if I did the limits right.
<@&286206848099549185>
@stiff hill Has your question been resolved?
@stiff hill Has your question been resolved?
@stiff hill 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.
for step 4 shouldnt it have been 0 <= theta <= pi?
it says above xy plane
oh above xy plane meant positive z?
,w yes
Welcome
.close
Closed by @scenic 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.
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
(2y - 5)^2
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
@mighty acorn Has your question been resolved?
for a curve f(x) rotated about the x-axis, yes this formula is correct
yeah, its 2pi times the integral of the function times the arclength between the endpoints
@mighty acorn Has your question been resolved?
@mighty acorn what part of your question has not been resolved?
@mighty acorn 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.
help please
<@&286206848099549185>
maybe find what v cross x is
!15m
Please only use the <@&286206848099549185> ping once if your question has not been answered for 15 minutes. Please do not ping or DM individual users about your question.
@astral smelt Has your question been resolved?
Closed by @astral smelt
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.
Could somebody explain to me why the answer to c is npi/2??? Ive solved a and be but I have no idea how that got to c?
the answers to a and b are
bouta waffle but i think its becasue cos(pi/2) = 0, that means that you would only count for the value of x ?
but if cos(pi/2)=0, that means it would be f(x)=cos (x)
and if you sub -x
so f(-x)= cos(-x)=cos (x)
doesnt that mean its even
c is just anything that's not a or b
can you show exactly what they've given as the answer for c)
it's here
ah, discord preview cut it off
they said NOT equal to
thats what i was thinking
f is neither odd or even iff (f is not odd) AND (f is not even)
not odd means not b and not even means not a
yeah and that agrees with their answer
i just dunnno why its npi/2😭
you have npi makes the function even and pi/2+npi makes the function odd
a number of either form here can be written as npi/2
all of those numbers are of the form npi/2
ohh okay
i kind of get it (no really) but i get the idea😭so the answer is just saying it cant be the answer for even or odd, and wrote it as npi/2 bc the answers to both are in the same form? (idk why tho)
if you list out the values from each set
0, pi, 2pi, 3pi ...
pi/2, 3pi/2, 5pi/2 ...
combining them
0, pi/2, pi, 3pi/2, 2pi, 5pi/2, 3pi...
same idea for the negatives
you'd get all the integer multiples of pi/2
Closed by @ocean knot
Use .reopen if this was a mistake.
you could still write excluding the sets from a,b
and get some marks without the final simplification
ohh okay phew
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
To ask for mathematics help on this server, please open your own help channel or help thread. See #❓how-to-get-help for instructions.
Hi, this channel is now yours. If you have a question, you can ask it now
@hexed shell
its a puzzle challanged by my friend does it count?
involves god damn binary
i need lat 50 bucks 🤑
Sure, if it's related to math
did your friend allow you to ask other people for help? Lol
@hexed shell Has your question been resolved?
is binary math or no
Yeah
just send the puzzle, if it doesn't fit in here, we could redirect you to the right server
but i'm pretty sure you are at the right place
Its a puzzle in game tho
check this out
I need to make "Binary" and then convert it into decimals after, im pretty sure you have to start on the top right and read it like opposite your reading a book
Do you just need to convert it to decimal system? (Normal numbers)
alright
can you write the sequence of lights as 1s and 0s
Alive should be 1 and dead is 0
yeah, but im not sure how to read it
is it like 11100?
the one on right
or 101 111 101 011 010
Actually, thats the thing. I dont know 💀
i think
you have to start
from top right
that would make it start with 0
that's not usual
but it would then be
010 011 101 111 101
if you just need to pass the game, you can convert it like this
,w 010 011 101 111 101 binary to decimal
Wolfram Alpha doesn't understand your query!
Perhaps try rephrasing your question?
Click here to refine your query online
yep
010011101111101
Otherwise you would read it from right to left and multiply each digit by corresponding power of 2.
1 * 2^0 + 0 * 2^1 + 1 * 2^2 + 1 * 2^3...
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.
hey does anyone know why this equation works?
why is bn equals to that whole lotta thing
cuz when I try to write bn in terms of cn I get bn+cnx{bn-1}
Its just multiplying and dividing by a number done multiple times
check the denominator of first term and numerator of next term
so like it cancels out?
yes
ah I see
you can say
Closed by @lilac gazelle
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.
@hollow iceI read what u typed but I don't get based upon what does he make up this formula
FG = Tr on G ... etc. etc.
@lavish umbra Has your question been resolved?
T R on G is just the force exerted by the rope on the gymnast
so in the frame of reference of the gymnast, since she is stationary, the forces must balance
so that force is equal an opposite to her own weight
because, any more force and she accelerates up, less and she accelerated down
weight is just mg, so we have the value 490N from that
In short, the forces have been balance on all the bodies in the solution. Each body has been considered separately and all the applied forces and their reactions are tracked. Since everything is in equilibrium, the net force is 0. So unknown reactions are found using the free body diagrams
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 find the angles for A,B and c
this looks like one of those notes from the slenderman game
can you please send a clean & well labelled diagram?
2,8 = 28/10 right?
no its 2.8
my spanish isnt good
then what's that
does 2.8 cm refer to the radius
This is portuguese
mb
?
Not spanish
Oki
I Saw that
Yes
well from this you can find the side lengths right
just add the radii
then use the law of sines
Here in europeu we do in centímeters
Closed by @manic meadow
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.
need help with part ii)
Please don't occupy multiple help channels.
.close
Closed by @foggy 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.
I am a bit confused if my understanding of conditional probability is correct. When talking about probability of an event, $P(A) = 0.3$, that means it has a 30 procent chance of happening in regards to the sample space $\Omega$. Does that mean thatr $P(B | A)$ is the probability relative to $A$ instead of $\Omega$? In other words, we are only interested in $B$ at the same time as $A$ occurs?
Pen
exactly
Phew, thought I was going mad for a second as my classmate is disagreeing
Thank you, Odina ❤️
.close
Closed by @floral lodge
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.
2+2?
75
Closed by @lyric gyro
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.
is it normal that I do not understand the solution
which part specifically do you not understand?
@lavish umbra 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.
The answer is incorrect but i believe i integrated it all correctly
this is the right answer
but with fubini's theorem the answers should be the same
you changed the bounds incorrectly
in your region you have (I believe) 0 <= y <= x <= 2
so you should be integrating w.r.t x with bounds y and 2, not 0 and y
forgot to send this too
This is how i found the bounds
is the y incorrect?
or x incorrect
I believe you're actually right, and the 'right' answer is the one with the mistake, now that I've actually seen what E is supposed to be
ok thank you very much
.close
Closed by @feral sun
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 guys, I need some help understanding the highlighted line, why do we need to generate 0?
@radiant rampart Has your question been resolved?
I'm not sure that it explicitly states why but I think i can make a guess now. Is it because when you generate the 0-vector (where all entries are 0), you effectively have a system of linear equations that all equal 0, which makes it easier to find a general solution?
<@&286206848099549185>
.close
Closed by @radiant rampart
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 explain to me as if I was 10 how to turn a polynomial function of second degree from a general form to a factorise form?
@uncut token Has your question been resolved?
<@&286206848099549185>
what do you mean general form and factorize form
like $ax^2+bx+c$ into $a(x-x_1)(x-x_2)$?
jan Niku
yes
okay, so you know the quadratic formula I'm guessing
ye
jan Niku
now do you know the roots?
wait u got me lost
okay, lets start with $ax^2+bx+c$
jan Niku
ok
I want to make the coefficient in front 1
for no particular reason
i anticipate it might make our life easier later
I could give u my equation if that helps
okay
one of them
2x^2 + 4x - 6
so first, factor off the 2
because its easier to work with stuff that has a leading coefficient of 1
it not what I have as a formula
oh yea
i mean, this will work when it works
its up to your ability to figure it out
i still think its easier to factor off the 2, first
ok so, if I factor 2,
it would be
2(x^2 + 2x - 3)
I did this earlier and erased it because I was stuck at a part
I’ll give u the full details in a few mins
ok so I did (b/2)^2 which gave me (2/2)^2 which result was 1
and then I did 2(x^2 + 2x + 1 - 1 - 3)
but this is the part I start getting confused
oh, maybe i dont understand this method
i thought you meant
the sum is +2
and the product is -3
okay but then why did you factor out 2
that was after we did any change
now you're working on two different polynomials
i would, and then work on x^2 + 2x -3
ye, and when I worked on it, I got 2(x^2 + 2x + 1 - 1 - 3)
it make sense so far
oh it all good
in french it called complétion de carré
I don’t know if it might help
its just not clear if you mean by inspection or specifically using the coefficient
which i guess you mean the second
completing the square?
but as far as im aware if the roots are idk w and z
yes
it wasn’t?
do you want form $a(x-x_1)(x-x_2)$ or $a(x-h)^2 + k$
I want the first one
jan Niku
right so completing the square is only useful for getting the first form indirectly
completing the square is usually nice because it tells you the bottom or top of the quadratic
the vertex
but it doesnt directly provide you the roots
and the roots are what you need to factor
oh so would u say it pointless in this situation to use it?
its a good technique to know and its important
its just not useful here as much as other methods, i think
im sorry i should have gathered thats what you were using earlier
I should be the one apologizing for not giving clear instructions
jan Niku
i think normally, someone would try to guess the roots here
but you could use other techniques too
how do u “guess” it?
do you know how to solve by inspection? i mean, just trying to guess
you know the product of the roots is -3
and you know the sum is +2
so, you try to think of two numbers that give you these results
can you think of two numbers that multiply to -3 and add to +2?
3 times - 1
3 - 1
yea
so then we know the roots, they should be x=3, and x=-1
then we can write it in the factored form, given the roots
its $2(x^2+2x-3) = 2(x-3)\qty(x- (-1))$
jan Niku
it works like this
oh wait nvm I understood it
the roots are where $2(x-3)(x+1)$ is 0
it just the formula
yea
jan Niku
well, we want the polynomial to be zero where x=3
so if you put in x=3, and then subtract 3
wait actually no,
in the textbook the answer is 2(x + 3) (x - 1)
f(x) = 2x^2 + 4x - 6
,w psolve 2x^2+4x-6=0
right, sorry, im being dumb
im over complicating it really
we could just write out $(x+x_1)(x+x_2)$
jan Niku
we know $x_1+x_2 = 2$ and $x_1 x_2 = -3$
jan Niku
ye
jan Niku
Closed by @uncut token
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 really know how to start this, i've tried some ways but they're wrong
can you show what you tried
Ok
- get the lengths of AB which is 8
but i have to determine the ratio between the areas of ABC and ABQ
which i dont really know how to do
did you make a diagram/sketch of the figure
nah i can't really visualize what the question is asking
which is why i'm struggling mostly
usually for things like nuumber theory it's ok but i'm weak in geometry
ok
this is what i see
but idk if it’s accurate
i thought i could go from AB=8 to finding the height, which is 10
but idk what to do from here
sry, I can see a way to approach this ATM, you may need to wait for someone else
im also doing it right now but i think theres something to do with the height from p to c
anyways this week seems way harder than the other weeks
Are you in the CEMC thing too??
yes
oh i see
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
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.
any hints as to how to approach this problem?
notice how this number is really close to 40000
yeah but we want integers
W guess and check
my first thinking was making it (a+b)^2-2ab
anyways you can square root 40501 and notice that its close to 201, and when you square 201, its 40401
which just happens to be the original minus 100
oh it only wants 2 pairs bruh
yes... so the idea is you guess an integer close to 200
the engineer way
well it's not even "guessing" since you should know what 201^2 evaluates to without doing any math
oh
i wonder if the fact that 40501 = 101 * 401 helps
thats a^2-b^2 unfortunately
no
sorry edited it
yea not sure what im supposed to do
i tried doing smth with the fact that 40501 = (10^2 + 1)(20^2 + 1) and after some sophie germain thing it led to
like 181 * 221 + 500 idt thats
helpful tho
<@&286206848099549185>
hi
Hi guys
Hi
@stable cedar 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.
@restive river 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.
Why hello! I'm trying to understand the ramanujan summation. Can someone explain how we got from step 4 to 5?
Remember that 1 + 2 + 3 + 4 + .... = C
Yeah but 1/4-c doesn't equal -4c
It's a derivation
supposedly they want B to be 1/4, maybe in an earlier step
sorry, earlier derivation
How can it be 1/4
each step has to follow from the ones above it
What even is B?
from the image, B is 1-2+3-4+...
Okay tysm
I think there was some nonsense assumption like 1-1+1-1+... should be 1/2 that they use to derive B
showing my true colors here, this is all nonsense
Yeah, that's an important point
this is all non-sense
because by saying "C = 1 + 2 + 3 + 4 + 5...", you already make the assumption that it converges to some number, but it actually doesn't
B = 1 - 2 + 3 - 4 + 5 ...
2B = 1 - 2 + 3 - 4 + 5 ...
+ 1 - 2 + 3 - 4 ...
2B = 1 - 1 + 1 - 1 + 1 - 1 ...
Yeah haha
A = 1 - 1 + 1 - 1 + 1 - 1 + ...
A = 1 - A
2A = 1
A = 1/2
.
@lusty sapphire is that at least somewhat right explanation? Or is my explanation also nonsense
Hence 2B = 1/2
and B = 1/4
well we can say C isn't even a real number
"1 + 2 + 3 + 4 + 5 + ..." just isn't a meaningful object, at least with the standard definition of summation
we're suggesting that C is the limit of the sequence of partial sums of natural numbers
this limit doesn't exist in the reals, hence C isn't real
same as how expressions like 1/0, or sqrt(-1) if you're working within the real numbers, just don't really evaluate to anything
This is the key point
This is outside of the idea of summations to infinity as we normally do them
Yeah, that's why we can't use standard rules of arithmetic to manipulate it
and algebra
Numberphile, of course, describes it
in fact the rules don't apply whenever a series doesn't converge absolutely
we can't permute the terms of a series freely because the resulting series post-permutation may not converge to the same point
In fact i think there is a theorem that says that by rearranging it, we can make it converge to anything
(or diverges)
it's true
look at the cesaro sum for one type of sum
that allows you transform a divergent sequence to converge
for instance, the divergent grandi series can be manipulated by taking its cesaro sum to give us a value of 1/2
digression but grandi's series is a really good example of something that does not need to be named after anyone lol
@edgy frost Has your question been resolved?
Closed by @edgy frost
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.
Hey i need help with a proof for linear algebra
swap Djk and Dkj and show that it evaluates to (DtD)t
@hybrid maple 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.
Need help with sequences
4,8,20,56,_
take the difference between those terms
It's a wierd pattern
When you take 4 common out you get 1,2,5,14
1+ 3^0 = 2
2+3^1 = 5
5 + 3^2 = 14
I'd say take 4 common out then subtract the sequence with itself shifted one place
To obtain a gp
Mb, keep going
are you trying to to find the general form or the sum?
Wlc
.close
Closed by @steep 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.
Its the intersection of angle bisectors
thats the definition
you can see the angles B/2 and C/2
@mild sorrel 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.
Assignment: Write the rational exponents in radical form. Simplify if possible.
- 2^1/5
- 10^-1/2
- 18^1/4
- (-3)^1/3
- 9^1/8
- 2^2/5
- 27^5/3
- 10^4/5
my answers in 1 is 5√2, 3 is 4√18, 5 is 8√9, 6 is 5√2^2, 7 is 243 and 8 is 5√10^4
are these correct?
I don't understand how to do 2 and 4 though
x^-1 = 1/x so 10^-1 = 1/10 now try 2 by yourself
i assume you mean $\sqrt[5]{2}$ and not $5\sqrt{2}$
artemetra
yeah
do you mutiply it 1/10 by 10/10?
For the second que?
yeah
No
false
wut
$x^{-n}=\frac1{x^n}$
kheerii
i think you meant (1/n)^x
Fck I fcked up sorry
n^ -x = 1/n^x
Yea I fcked up
so like, (1/10)^2/1 then 1^2/10^2?
then 1/100?
huh?
@humble wren Has your question been resolved?
why 2/1
only the sign changes for the power
so it would be 1/2 instead of -1/2 when you bring the whole thing down
thats how they got 1/sqrt(10)
@humble wren Has your question been resolved?
OHH
i thought you would need to like find the reciprocal of -1/2
nah
I mean how they form BQ forms the angle bisector
@humble wren 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.
is this right
@lavish umbra 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.
No
Q: ABCD is a rectangle, <DBC is 55 degree.The diagonals AC and BD intersect at point O.Find <AOB.
repost yo question
ABCD is a rectangle
<DBC is 55 degree
we dont know AOB
AC and BD intersect at point O
at the middle
So we have to find AOB
@lavish umbra 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.
Do the graphs around double zeros ever form in quadrants 3 or 4? As, in will double zeros ever yield negative y values? If so, how?
I'm confused because I know you can't get a real negative value from squaring something, but if it's possible to get a negative graph from double zeros, then I'm confused how the function makes that happen.
would it just be a negative "a" value attached to it? like f(x) = -(x-h)^2
oh wait, i can just use desmos to find out. my bad yall
.close
Closed by @rose charm
Use .reopen if this was a mistake.
i
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
$
A
\begin{bmatrix}\frac{1}{2} & \frac{1}{2} & 0 & 0 & \dots & 0 & 0 \ \frac{1}{3} & \frac{1}{3} & \frac{1}{3} & 0 & \dots & 0 & 0 \ 0 & \frac{1}{3} & \frac{1}{3} & \frac{1}{3} & \dots & 0 & 0 \ \vdots & \vdots & \vdots & \vdots & \vdots & \vdots & \vdots \ 0 & 0 & 0 & 0 & \dots & \frac{1}{2} & \frac{1}{2} \end{bmatrix}
$ and let $x = \begin{bmatrix} x_1 & x_2 & \dots & x_n\end{bmatrix}^T$.
How to prove, that
$
\lim_{k \rightarrow \infty}
\prod_{i=0}^{k}
s_i A x
$
where $s_i \in (0.8, 1.2)$
will have all vector elements close to the same?
redve
I use similar algorithm to "smooth up" a vector, and I wanna formally prove it smooths up the vector
and finally got this limit
@ashen vault Has your question been resolved?
<@&286206848099549185>
@ashen vault Has your question been resolved?
.close
Closed by @ashen vault
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 , if i know the equation of a line in space , can i find the equation of the planes that their section is that line ?
and how ?
there are infinitely many pairs of planes such that their intersection is the same line
@dense lynx yeah i know but how we can find 2 of them that aren't parallel with each other ?
you can plug the parameterized version of the line into the equation of a plane Ax + By + Cz = D and find values of A, B, C, D that fit
Closed by @west mulch
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 I need help and understanding what operations to do and in what order
I know how to solve for a already
a) P(x) =-0.4x^2+55-12
Although when it comes to section B I kind of start getting confused can you help me understand what order and how to do it please
<@&286206848099549185>
You just use 100 as x
You put 100 into formulae R, C and P instead of x
Can you walk me through it? I'm sorry I tried but I must have messed it up
<@&286206848099549185> can someone help me walk through this so I have notes? Sorry I want to know step by step so I don't mess up please 🥺
Thank you for the help Seb just need little more info cause I mess up easy
Please don't ping helpers unless your post hasn't been visited for 15 minutes
Oh I waited 15 I thought sorry!
R(x) = 59x - 0.4x²
you would get R(100) by keeping x=100 i.e.
59(100) - 0.4(100²)
for simplification you can solve it as
100[59-(0.4)(100)]
same thing goes for C(100)
and once you get R(100) and C(100), subtract them and get P(100)
Okay ❤️ thank you very much I will try now 😄
if
f(x) = 10x
then what is
f(10)?
i just want to make sure you understand the main part behind it
Haha ty Vansh 💜❤️
np
Closed by @old yacht
Use .reopen if this was a mistake.
Sorry I didn’t see 😭 you can ping me personally next time.
@dusky coral no worries ty for the help!
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.
,, 2\pi \cdot \frac{11}{\sqrt{7}} \int_0^{28} x^{\frac{1}{4}} \cdot \sqrt{1+ax^{-\frac{1}{2}}}
𝔸dωn𝓲²s
𝔸dωn𝓲²s
Let $u = 1+ax^{-\frac{1}{2}}$
𝔸dωn𝓲²s
brb
ok so then
,,\frac{du}{dx} = -\frac{1}{2} \cdot a \cdot x^{-\frac{3}{2}} \Leftrightarrow dx = - \cdot \frac{2}{a} \cdot x^{\frac{3}{2}}: du
𝔸dωn𝓲²s
,,- 2\pi \cdot \frac{11}{\sqrt{7}} \cdot \frac{2}{a} \int_1^{1+\frac{a}{\sqrt{28}}} x^{\frac{1}{4}} \cdot x^{\frac{3}{2}} \cdot \sqrt{u} : du
𝔸dωn𝓲²s
,, x^{\frac{1}{4}} \cdot x^{\frac{3}{2}} = x^{\frac{7}{4}}
𝔸dωn𝓲²s
Let's see if the substitution helps
no
we have to write x^7/4 in terms of u
$u = 1+ax^{-\frac{1}{2}} \Leftrightarrow x^{-\frac{1}{2}} = \frac{u-1}{a} \Leftrightarrow x = \frac{a^2}{(u-1)^2}$
oh I forgot a
𝔸dωn𝓲²s
,,- 2\pi \cdot \frac{11}{\sqrt{7}} \cdot \frac{2}{a} \cdot a^\frac{7}{2} \int_1^{1+\frac{a}{\sqrt{28}}} \frac{1}{(u-1)^\frac{7}{2}} \cdot \sqrt{u} : du
𝔸dωn𝓲²s
ok i hope so far so good
I am thinking if that's the good way
that's what I am thinking
Maybe do another substitution
but first let me see if the previous stuff is correct
ok should be fine
Maybe let's try $z = \sqrt{u} \Rightarrow \frac{dz}{du} = \frac{1}{2z} \Leftrightarrow du = 2z : dz$
𝔸dωn𝓲²s
,,- 2\pi \cdot \frac{11}{\sqrt{7}} \cdot \frac{2}{a} \cdot a^\frac{7}{2} \cdot 2 \cdot \int_1^{\sqrt{1+\frac{a}{\sqrt{28}}}} \frac{z^2}{(z^2-1)^\frac{7}{2}} : dz
𝔸dωn𝓲²s
z²-1 = (z-1)(z+1)
hold on
Maybe a trig sub
😂
getting worse and worse
z² - 1 we could make use of sec²(x) - 1 = tan²(x)
but is there another way other than trying
Let $\sec\theta = z \Rightarrow dz= \tan\theta\sec\theta : d\theta$
𝔸dωn𝓲²s
,,- 2\pi \cdot \frac{11}{\sqrt{7}} \cdot \frac{2}{a} \cdot a^\frac{7}{2} \cdot 2 \cdot \int_0^{\arcsec(\sqrt{1+\frac{a}{\sqrt{28}}})} \frac{\sec^2\theta}{\tan^7\theta} \cdot \tan\theta \sec\theta : d\theta
,,- 2\pi \cdot \frac{11}{\sqrt{7}} \cdot \frac{2}{a} \cdot a^\frac{7}{2} \cdot 2 \cdot \int_0^{\arcsec(\sqrt{1+\frac{a}{\sqrt{28}}})} \sec^3\theta \cdot \cot^6\theta : d\theta
didnt help shit
ah no i did a silly
,w sec(x)cot(x) = csc(x)
,,- 2\pi \cdot \frac{11}{\sqrt{7}} \cdot \frac{2}{a} \cdot a^\frac{7}{2} \cdot 2 \cdot \int_0^{\arcsec(\sqrt{1+\frac{a}{\sqrt{28}}})} \csc^3\theta \cdot \cot^3\theta : d\theta
𝔸dωn𝓲²s
,w cot^2(x) = csc^2(x)-1
,,- 2\pi \cdot \frac{11}{\sqrt{7}} \cdot \frac{2}{a} \cdot a^\frac{7}{2} \cdot 2 \cdot \int_0^{\arcsec(\sqrt{1+\frac{a}{\sqrt{28}}})} \csc^3\theta (\csc^2\theta - 1) \cdot \cot \theta : d\theta
𝔸dωn𝓲²s
Let $w = \csc\theta \Rightarrow d\theta = -\frac{dw}{\cot\theta \cdot \csc\theta}$
𝔸dωn𝓲²s
,,- 2\pi \cdot \frac{11}{\sqrt{7}} \cdot \frac{2}{a} \cdot a^\frac{7}{2} \cdot 2 \cdot \int_{\arccsc(\arcsec(\sqrt{1+\frac{a}{\sqrt{28}}}))}^{\infty} w^2(w^2-1) : dw
𝔸dωn𝓲²s
This never exists lmao
not the only way
maybe there is a much smarter way
did you create that integral?
what surface area formula
,w Integrate[x^1/4Sqrt[1+a/Sqrt[x]],x]

