#help-26
1 messages · Page 3 of 1
2
Which are?
the first two terms?
Yep، you have only a, right?
yeah
-4-a^2?
(1-a)^2-(5-a)^2=0
Both sides of the equation ate c^2
We subtracted them, remember?
You only need to solve for a now. Expand both (1-a)^2 and -(5-a)^2, collect the terms and then solve for a
I’m so bad at this
I can’t even figure out a problem
Show example
Not really
a^2+2ab+b^2
You should work on on your algebra, stuff like binomial and the like are essential
ok
Try applying the above formula to 1-a and 5-a
alright, hold on. I can simplify it further
can you just give me the answers please. I will never figure this out and I have homework checks so if I haven’t done it I will get a 0
I'm sorry, I can't just give you all the answers as that's discouraged.
This is impossible 😓
Do it slowly. You know systems of equations so I reckon you're good enough to understand this
I don’t know how to do it though
Okay, for expanding (1-a)^2, try thinking of it as (1-a)(1-a)
yeah
Do you know how to multiple two expressions like this?
Ye
Yep exactly
See? You already know how to do it. My fault for complicating it with all the unnecessary equations.
You can now solve (1-a)^2-(5-a)^2=0
Yup, just one thing. Don't forget to change the signs. You're subtracting (25 -10a +a^2) so what happens to the signs?
i have to go to sleep in 10
minutes and i only answered 2 questions when I’ve been doing this for like 2 hours😕
oh yeah you flip?
Yep, now you can very easily solve for a
a=3
Yep
then what?
Now to solve for b, you use the same process
but where is the b term
Go back to the 3 equations you wrote earlier
here
Yep
What do you do?
plug in 3 for a
You can, and that's not wrong perse. but there is a way to get rid of all the a's like you did with the b's before
Look at the second and third equations
ok
Do they both have (5-a)^2?
you can eliminate the (5-a)^2
Yep
yeah
You can also eliminate c^2
And b becomes the only unknown variable
Try solving for b now
Ywp, watch out for the signs
it’s supposed to be 36-12b=0 then -12b=-36 then b =3
Yay
You found a and b
so what is C
How do you find c now?
You can use any of the 3 equations 
ok let me try
You know both a and b
but idk what to do
2
Square it
then 2^2 is 4
6-3=3 3^2=9 4+9=15
Then square it
15=c^2
ok
Plug a, b and c into the general formula of the circle
Wait what
And you have your equation
(x-a)^2+(x-b)^2=c^2
Correct for the most part. One little mistake though, c
c^2=15, so c= sqrt 15
oh
You wrote c^8
wdym
C=sqrt(15)
C^2=15
C^3=15sqrt(15)
.
.
.
C^8=15^2
Put c^2, which is 15
You can use this same method for all the other three point questions. It's a bit of a doozy but not very complicated one you get the gist of it
Now you can graph it if you want
How would you do that
@spring ivy 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 does the highlighted step work, like why does it equal -1
yes
Now, what is the range of sin(2x+30)?
There is only a change in phase and frequency, not amplitude
Look at it in relation to y
is that the period that im trying to find
What happens to the sinx graph function if you write sin2x, sin4x, sint 6x, etc etc?
The angles complete full 360 rotations faster
And so the frequency gets faster
And the graph gets squished sideways
But does this change the peaks?
No, it only reaches the peaks faster
That's why the range stays the same
No more values in the range, it still is -1 and 1
okok
Now which extreme would make y bigger, -1 or 1?
Keep not that you're multiplying by -4
-4 times -1 or -4 times 1?
-1
and the thing given is 0<x<360
do i have to change that
because the answer has 2 values
so like 30<2x+30<2(360)+30
No you don't need to do that
I'll explain what to do with it shortly, first, solve for x
ok so 2x+30 = 270 right
Not quite, you're missing some things
then x = 120
Sure, it's easier. But it won't give you all the answers
Sine repeats ever 360 degrees, but note that when you divide by 2 to solve for x, you're also dividing 360
That gives room to a second solution
X=120+180k
Now you try out possible values of k
This is where 0<x<360 comes in
ohh okok
If k= 0, what does x equal?
120?
300
Yep
OH okok i understand this now thank u
Closed by @deep creek
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.
while doing completing square why the leading co-effiecent should be 1?
It comes from what completing the square is
(Worst answer ever)
The visual proof and the algebraic derivation of quadratic formula
not necessary
the leading coefficient is divided out
are u sure?
I have seen the geometric proof and how to do the process but just curious
yes
You can always factor out the leading coefficient and then you have different b and c term
so, it's not necessary to make leading co-efficent 1?

okay, it's all because of that geometric proof we have to isolate the co-effiecent
?
@inner oracle you want to get in the weeds with this one? I am a little distracted rn tbh
We're trying to take advantage of this identity:
x² + 2kx + k² = (x + k)²
Perfect square trinomial ^
I'm sure there's a similar identity that includes a leading coefficient, but why make it more complicated?
kaynex probably
We can just factor that out, and use our simple method
I mean when we divide something we get fraction which is more complicated?
Watch this
ax^2 + bx + c
Factor out a
a(x^2 + (b/a)x + (c/a))
You would still get fractions, but they would appear mid-process
But now you still have a polynomial with 3 terms
a(x^2 + bx + c)
And we are back to the same problem anyway
In the general case
For the last time I Am asking it's necessaly i mean purely necessary to have co-effecient 1 while doing perfect square process ?
Closed by @little cloak
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 I'm not really good in factorization can someone help m
I get lost
the first line is where i have struggle
sorry can you repeat
does the numerator look like this
well, im not really good in factorisationm
ok let me show you
can't I like expand?
at the beginning??
yea right away
why
idk factorisation is hard
I always have trouble
is there a trick I can always do to always get it right
idk from where to start
wait
take your time
i forgot to add x^2 - 4x to this one so just ignore this
yes
just one question
this is way better
you gave the minus of -8 to the a
in the third line?
and combined (x-2) together to get (x-2)^2
yes
the 8 is a common factor
so i took it out
there are two (x-2) so that makes (x-2)^2
and then two (2) so 2x2=4
yes
do you understand it now?
ok let me expand my working a bit more
thank you
yes
well you can take both 8 and a out at the same time
but i was just showing you in more detail
but expanding it won't get me the same answer?
oh you mean at the beginning
Okay
ty
if I have an 8 outside as common factor and one inside
I remove one of them/
?
well if you take out the 8 then you remove the inside one
@coral fog 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.
hi
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I have a 7th grade geometry question so it’s probably easy for you guys but anyway. Here is my problem, and I need help how to work it. Our notes are terrible.
I Will send picture now
I have to use a1 over a2 = s1 over s2
Im about to go to school I need help 💀
if the two traingles are simillar the proportion between the same sides are equal
for exmple, 6.25/5 = x/8
in ur picture
if only the two triangles are simillar
Ok thanks so much
Also though
Which one do I square because we said we had to square it
sqaure what
Normally it would be a1/a2 =( s1/s2 ) squared
@nova tinsel Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
What is the question
Find the center and radius of the circle equation
I already did it, here is the evidence:
The center is already good
but the center i'm not sure
Cause I need to simplify
@rain radish are you there?
Do you know what completing the square is
yes
Is it the radius you still need?
yeah?
You square root it to get the radius
cause they told me it was 69/4
Who told you it was 69/4
That’s what I got
and not 69/4
yeah like that
That’s it in it’s simplest terms
ok I got it
Thank you so much @compact sigil
btw can I add you as a friend?
Yeah sure, and no problem! :))
ALRIGHT!
Oh also if you could help me solve also these problems which are related to the same topic:
I will do it also right now but I will show you if my procedure it's correct 🙂
Yeah no problem
@viscid saffron Has your question been resolved?
@compact sigil I already did it
the second point
the radius I don't know what it is
@compact sigil
That’s what I got
If you divide 1/3 by two you get 1/6 you forgot to do that when completing the square
wdym?
if (1/3)^2 is 1/9 from where 1/6 does it come from?
When you complete the square you remove the x from the x term and divide by 2
wait let me check
@viscid saffron 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.
idk how this works but hope im doing this right: probably a really basic question but whats the chances of throwing a pair with 5 dice? (exclusively any pair and the other 3 dice being distinct from one another / unique)
@deep heron 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.
Can someone help me understand the work for this problem?
We got that the series is 5/4, which is greater then 1 therefore it diverges
but I'm a little confused on the algebra and simplification, especially for the factorials
like which part?
Do you see the 2nd two red circled parts?
The one with (2n)!/(2n+2)!
What is Thomas Sowell doing here?
I do not understand how the denominator turns into (2n+2)(2n+1)2n!...perhaps I still do not understand how factorials work..
k! = k * (k-1)!
your 'k' here is 2n+2
Eaz as fuck bro
so (2n+2)! = (2n+2) * (2n+1)!
do it again to (2n+1)!
So (2n+1)! = (2n+1)*2n?
i just didn't pay attention to this in class, finals have had me drained.
well, (2n+1) * (2n)!
Right, do you mind if we go over a ratio test problem together?
@distant lintel Has your question been resolved?
if you want to work one out and let me know when you're stuck, sure.
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
Do you know what a Pythagorean triple is?
I think i do
im just confused because this problem the numbers have square roots on them and im not sure what to do
i figured it out
4=7
@keen solstice Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How would I go about 13. a)? I know it has to do something to do with spanning sets in just not sure how to go about it.
@frosty heart Has your question been resolved?
I got as far as a(-1,2,3) + b(4,1,-2) = (-14,-1,16) and then -a+4b=-14 , 2a+b=-1 , 3a-2b=16
@frosty heart Has your question been resolved?
<@&286206848099549185>
Let’s recall some equivalent way of saying three vectors does not lie on same plane
- They are linearly independent.
- The volume of the parallelpiped formed by these three vectors is not 0.
Maybe we can start from (2), can you recall how to compute such volume? And how does it lead to your desired conclusion?
Wait do I just have to solve for the scalar multiples and have my my LS=RS check to fail?
Closed by @frosty heart
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
@lapis iron 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 this?
@icy lagoon Has your question been resolved?
<@&286206848099549185>
<@&286206848099549185>
<@&286206848099549185>
sorry trying desperately not to make stupid algebra mistakes
solving f'=0 you get a form for x
then uhh
f of that x should be 4/3 or 2/3
i guess and, really
yea
man idk
i can get an expression completely in terms of a
and thats all fine but idk how to turn it into a range of possible values
theres only one solution
or how to set just the bounds of the function as the global mac
max and min
oh ok
yeah will ive got
somewhere around -sqrt(2)
,rotate -90
ignore the quadratic bit its the same answer
jan Niku
does this get you to $\mp \frac{1}{3\sqrt{-3a}} \pm \frac{1}{\sqrt{-3a}} + 1$
jan Niku
Wilsonkhann
inspection
the same thing you did with your x i think
im not sure its any nicer
plug it into f
try to simplify it
i have to fall asleep or im gonna die
if you do manage to solve this congrats, seems really annoying
Closed by @icy lagoon
Use .reopen if this was a mistake.
(Pssst. Instead of the internal-local-extrema solution, start by looking for an a that makes f(-1)=4/3 and f(1)=2/3, and then check whether the endpoints of that are actually global max and min on [-1,1] ...).
(Then look for an a that makes f(-1)=2/3 and f(1)=4/3)
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.
Closed due to the original message being deleted
Because of this
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.
Who can help me with my ixl
Ive been on it for a total of 6 hours and haven’t passed yet
What's your question?
One sec
@neon iron Has your question been resolved?

Its not uploading
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.
Closed due to the original message being deleted
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
✓(16-x^2)+✓(9-x^2)=5
AustinU
Let u²=9-x², then your life is a tad easier
I calculated and at last I got
2x^4-27x^2=|144|
!show
Show your work, and if possible, explain where you are stuck.
By squaring both sides
you messed it up somewhere
Squaring both sides isnt bad idea, as long as you know that it might generate extraneous solutions. It will make it really easy because 16+9 will cancel with 5^2. You just messed up the algebra
Alr Im redoing it
Maybe
You should plot the graphs for $f(x) = \sqrt{16 - x^2}$ and $g(x) = 5 - \sqrt{9 - x^2}$
NEONPerseus
They're both semi circles and pretty easy to plot
Wait the second one isn't one is it
,w plot y = 5 - \sqrt{9 - x^2}
I solved it
Good on you
.close
Closed by @main ibex
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 my gcse maths revision, got 6 days, if anyone could tutor me a bit too I would appreciate it very much
Stuck on this question
@neon iron Has your question been resolved?
@neon iron Has your question been resolved?
well @neon iron, your goal is to isolate the variable. You have to think in an operation kind of way. Let's try it on 4y + 5 > 12. First thing, look at additions and subtractions. There's an addition on the y side, so since 5 is being added, you need to subtract it from both sides giving you: 4y + 5 - 5 > 12 -5. Now we now 5-5 = 0, and 12 - 5 = 7 giving: 4y > 7. Next, we see that there is a multiplication next to the y. Since the 4 is multiplying, let's divide it on both sides giving: 4y / 4 > 7 / 4. 4/4 = 1, meaning: y > 7/4. You could enter 7/4 in your calculator, but it would give an approximate answer, so I'd suggest leaving it at that. It's not all that complex when you think about doing the opposite of what's happening on the variable's side.
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.
there are 3 trigonometric ratios to consider: sin, cos, or tan
compared to the angle we're given, which two sides do we have (out of opposite, adjacent, hypotenuse)
which one is which
The trig function you use is based on the perspective of where the angle is
adjacent means it's touching the angle
we've established that we have opposite and hypotenuse. So what ratio involves those two sides?
so let's write out the sin ratio, plugging in the values we know
Closed by @left lynx
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 a, b and c are positive constants show that all solutions of the DE ay''+by'+cy = 0, tend to 0 when x --> infinity.
I don't how to do this, my equation is ar^2 + br + c = 0, then I have 3 cases, when b^2 - 4ac > 0, my solution is y(x) = c*e^r1x + de^r2x, if I calculate the limit x ---> infinity, it's equal to infinity no 0, and the other cases are similar, then what I have to do?
@uncut agate Has your question been resolved?
.close
Closed by @uncut agate
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 work this out?
Chain rule.
Closed by @blazing crescent
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.
we finished derivatives a while back and then started integration, my teacher repeatedly says unlike derivatives integration is much more limited and differentiation is possible in a lot more cases unlike integration
When we studied derivates before that we studied differentiability so I could actually tell if a function is differentiable at some point in its domain, how can i say the same for integrals?
basically when/how can I conclude a function is non integrable?
There are different notions of integrability, for the most basic ie Riemann integration. A function is Riemann integrable if the measure of its set of discontinuities has measure zero
For a simpler case, if the function is discontinuous at finitely many points then it is Riemann integrable
Something like sin(x)/x, that is?
Wdym?
sin(x)/x even though is discontinuous at x = 0, it is integrable?
In an interval that includes 0
,w int sin(x)/x from -1 to 1
sinx/x is also called the sinc function
And since it is an even function the integral can be simplified
Yes although it's not a proper integral if the limit involves infinity
You know how integral is taught as taking rectangles and adding their area. Then in the limiting sense the sum of the area approaches the integral. This notion of integration is called Riemann integration
Then there's a more advanced notion of integration which uses the concept of measures to define integration. It is called Lebesgue integration.
didn't Newton/leibniz found integration, is their notion not that?
What they did was in an intuitive sense. The proper theory of integration took much longer to form and is different than what they had in mind. In fact the concepts of limit that we use to define integration cause after Integration.
It gave birth to whole new areas of maths called real analysis and measure theory
usually when teachers say this they mean the methods we have for finding an antiderivative are more limited than derivatives. We can find the formula for the derivative in a lot more cases, but it's very easy to find something that you can't find a simple antiderivative for, or where basic methods break down.
yes, we can always pretty much use the first principles for derivatives, is there no such thing for integration?
i guess not
like, the integral for e^(x^2) requires some more advanced techniques than 'power rule' or 'by parts' methods.
,w integral of e^(x^2)
that's not so good
i get what you all mean
one last question
when would someone typically see an integral like e^(x^2)
And this result, 1/2sqrt(pi)erfi(x)
(whatever the heck that means)
You'd find some interesting integrals while doing advanced physics
not maths?
Not much unless you're solving differential equations
i did find some integral in physics last session that apparently had something to do with gamma function and so we had to skip it
i see
alright!
thank you both!
.close
Closed by @dense nova
Use .reopen if this was a mistake.
see elliptic integrals as well as the error function
.reopen
✅
any source you'd recommend
elliptic integrals appear when studying pendulums for example, while erf describes heat flow in simple cases
not really anything no. These are things we talked about in class, and that very recently came up in a french exam paper
which exam paper?
Mines-Ponts 2023 MP physique 1
nice
the paper decided to take classic problems for which you usually approximate, and use some more heavy machinery to do them without approximating
using the lambert W function, elliptic integrals and the error function in 3 separate studies
free falling body with friction, period of a pendulum, heat flow
also talking about simple problems, i remember a physics problem which deals with electric fields, would you mind if I shared it here/expressed your views on it
of course I'll take this elsewhere as well later today, as this isn't a physics server
I'm not much of a physics guy but feel free to go ahead
it has something to do with electric field at a point which is not at the centre, but very near it, like it approaches the centre you might say, the centre is of a uniformly charged ring
cant you send an image ?
this question was given to me by my teacher once I asked him to give an expression for electric field by the same ring at a point near the ring
So basically there's no original problem, let me explain
we were studying electric field, and so we studied electric field due to a ring with uniform charge distribution
Then he told us it is supposed to be zero at centre and we wrote an expression for electric field at its axis
Later I asked about the electric field at some point on ring, if that makes sense
And he said it isn't possible to do that but it is definitely possible to find gje electric field at a point just near the centre
I claimed its zero but he said its only zero at the exact centre, nowhere else and he kind of makes sense, so that is the question he has given me for the time being
I'm sorry I don't have any image
what do you mean by ring more precisely ?
a flat one with a width, a cylinder with a thickness, just a circle ?
with lineic charge density ?
a charge generates potentiel q/r
the potential at a given point would be the integral of q/r over the circle
then you need to find r(theta)
let the circle have radius R, the point be a distance d from the center
r² = x²+y²
(x-d)²+y²=R²
r² = R² - d² + 2dx
x = d + R cos theta
,w integrate 1/(k + cos theta) from 0 to 2pi
how's (x-d)^2+y^2 = r^2
I center the point at the origin, and offset the circle
isn't that an approximation already?
,w integrate 1 / sqrt(k + cos(theta)) wrt theta from 0 to 2pi
the point was near the centre but you wrote the equation of the circle considering the centre was located at that point
let the point be at (0, 0)
the circle is centered at (d, 0)
i see, okay. that's that.
but it is doable?
algebraically ?
computers can always find things to arbitrary precision
in practice
but if you're going this way, might as well compute the field directly
wait
that removes the sqrt doesnt it
the field is q/r² er
er = cos theta ex + sin theta ey
then you integrate
q/(R²-d² + 2d(d+R cos theta)) cos theta for the x component
,w integrate cos theta / (k + cos theta) wrt theta
not pleasant
,w integrate sin theta / (k + cos theta) wrt theta
so technically you can find the field. But that's not exactly elegant
especially plugging in the value of k and finding the outside constant
makes it even uglier
i see, I'll try it in this way and see where that leads me
of course I'll also be using software for most of the integration
to pain and suffering according to all available evidence
well this question is merely a fun problem so i can send my teacher anything of the sort its not like im doing the hard work anyway haha
also don't forget the 1/4pi e0
but yeah very ugly
Closed by @dense nova
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.
Any idea to solve it with series?
do you even need series? direct substitution works just fine here
sin( (y-a)/2) approaches sin(-a/2) and tan( (πy)/(2a) ) approaches tan(0) = 0
@undone flicker Has your question been resolved?
Tan 0 how?
Can you please explain how it approaches? Did you put the value of y directly?
,calc tan(0)
Result:
0
this is a standard fact from trigonometry
What do you mean say clearly?
I am not asking value of tan 0
My question is how tan 0 comes here if we put y = a it becomes tan pi/2 which is infinity
you're doing this limit problem right?
Ohh wait
It's 0 i thought it's (a)
So what next step
Here we have got sin(-a/2)× tan 0 which is zero so all value will be 0
Zero is not the answer
answer to what
To this
What will be the next step
??@sweet shard
why do you think 0 is not the answer
don't understand what you're saying
Here we have got sin(-a/2)× tan 0 which is zero so all value will be 0
this is correct
Sin(-a/2) × tan 0 = sin(-a/2) × 0 =0
so why do you say zero is not the answer?
.
I guess the limit confusing
these two are different problems
this is not "answer sheet"
Yeah but look at the question/solution
They added a different answer sheet to the question
it's a different question
read.
Yes got it thats the confusion
Even I didn't notice it while reading the solution
So tell me now how to solve it when limit tends to a
I meant what approach?
No i don't want to solve it through this as I have clearly mentioned here
I want to solve it with any other method if it has an expansion of a series of something
that was for a different problem
then use taylor series up to order 2 or 3 for both sin and tan
Show
,rotate
Ohh wait a minute then. It's messy
Yes. I followed this
Sinx and tanx i put value of x too
Then I multiply it but it becomes zero
You just did algebra wrong probably
I see, let me try it again clearly then show you
It was messy so maybe my mistake
@sweet shard
Is this correct? Please check
@undone flicker 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.
If n(A)=4, n(B)=5 and n(A∩B)=3, then n((AxB)∩(BxA)) is?
Is answer 8 or 9?
n is cardinality ?
Cardinal number, yes
no of elements in set A is what my teacher call cardinal number of set A, represented by n(A)
What is the title of the lesson?
Relation and functions lecture no 8
Sir was doing test revision
And it was a question asked in that revision
So no specific title for lesson
Also it is not this specific question
The question asked was if n(A)=3, n(B)=4 and n(A∩B)=2 then n((AxB)∩(BxA))=
I simply edited the original question
No worries
I got answer through lengthy example building
Answer is 9
Did u find a detailed answer?
Yes I guess, it was through example building but it's one lengthy method
I have a new question though.
If I have 3 elements in a set and I want to make every possible pairs out of these 3 elements, how would I do that?
I also found the solution in my notebook, but I did not find how to explain it to you because my lessons are not in English, sorry
It's okay
I'll ask new question from fresh channel
.close
Closed by @merry mason
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 you are picking every possible pairs out of 3 elements then 3p2 which is 6 is not the answer because this doesn't make (a,a) , (b,b), and (c,c) pairs btw
@safe burrow I think I needed to tell you this
so it's pair drawing w/o replacement?
Yes
I kind of missed it that's why I said 9 because from another method that was the answer
for a set with n elements, that's just n(n-1)
Ohh
which is still 6 though, because n=3
since you have n choices for the first element, and (bc you cant pick that again) n-1 choices for the next
and last
Shouldnt be n^2 though
yeah. if your choices are a, b, c, you get
ab
ac
ba
bc
ca
cb
And aa, bb, and cc
Don't we consider them as well?
Permutation function completely missed them
i thought you couldn't pick the same element twice?
was that not the whole point?
If we are making Cartesian product we can do that
if we can have aa, why did you say yes here?
It's also my problem, I forgot to mention you that we can pick same elements as well 😔
Ohh
I couldn't comprehend that well then which is why I said yes
Now I understand
Also thanks for your help, I have fixed this now
.close
Closed by @merry mason
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.
girll im royalty
bow down
😭
but srsly i need to say thx to everyone who helped my pass my final
huges
does her majesty have a maths question
Closed by @radiant tapir
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.
lmao sup again
sup xD
you will have to answer that yourself, since it's not given then assume it's not at first, you have two options it's either touching on the bases or on the sides
im also not too sure about the properties of a circumcircle
hmm thinking about it, would be dumb to have a circumcircle who doesn't touch all vertices
it is safe to say circle touches every side of the trapezoid @digital sleet
this is just a guess but would a line connecting two opposite endpoints be the diameter?
it would yes
cause ik thats the case for a right triangle but idk bout an iscoceles trapezoid
alr
wait thats an incircle
you know the sides, you know the bases, find x, and solve for height
the height is 4sqrt2
oh well
i apologize i was thinking it was inscribed all along
you need to find it's diagonal
always draw a picture
The diagonal isn't the diameter of the circle, is it?
idk ig thats what we're assuming
If it is, then you've got a rectangle, not a trapezoid
nop it's not 💀
oh then what do we do lmao
so middle of the trapezoid base to it's touching side
is a radius?
nop
not it aswell
lemme draw some more
circumcenter to a point is
but idk an properties bout that lmao and google isnt giving me any
I've tried a few things but I'm not really sure
I tried assuming the base of 10 was the diameter but that's definitely not true
goddamn should have learned more about trapezoids
@digital sleet what are these questions from
When you draw the diagonal, you make two triangles, and the circumcircle of the trapezoid is also the circumcircle of both triangles
which means the point where any of their perpendicular bisectors intersect is the center of the circle
I have to go in a minute but that seems like a path
mathcon
@digital sleet Has your question been resolved?
.close
Closed by @digital sleet
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
.reopen
Hello again. It's closed by both. You didn't respond
Closed due to the original message being deleted
@sweet shard
@drifting swift
Don't ping specific people
Here is another question but the limit changed only. This is what I tried
@empty sail we were trying to solve
Above but closed the question by bot
That was hours ago
So, don't ping specific people
wish i could figure out how to approach this