#help-49
1 messages · Page 169 of 1
where is -1/2 * -2 * x * x^3/6 from the expansion of -1/2(x - x^3/6)^2?
oh wait no i do see the x^4/6
it disappeared afterwards tho it looks like
wait a minute...
i mean the x^6 term should have been trashed also
you trashed too much but this time you were lucky
What do you mean by trashed?
If i take only one term of it then
(1-x^2/2-1+x^2/2)/x^4 which is 0
.close
Closed by @molten bay
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 do just the number and algebra row in the table provided given the instructions included about statistics Measures of Position and Central Tendency
have you done anything thus far
i've did the median
have you sorted these things in ascending order
but i'm not sure if its right since i've only tried
ok im gonna take your word for it that the median is correct
so now what else do they want you to find
the quartiles?
how about the table?
can you help me correct the table
id like to see the original data sorted in ascending order and ungrouped
sure
dont rly wanna do it myself cause it's a bit energy-consuming
do i still have to tally it?
Ascending Order: 20,28,28,32,32,32,36,36,36,36,44,44,44,48,48,48,48,48,48,52,52,56,56,56,60,60,60,64,64,64,68,68,72,72,76,80,84,84
is that good enough??
what's next??
ok so that's 28 data points
20,28,28
that's 3 points that go in the20-29class interval
and you put 2 as that interval's frequency

oh yea mb
its confusing 😭
what else did i miss
wait
is it correct that i can do up until 89 if the highest interval is 84
the highest score you mean?
ok sorry im finding myself too unfocused to continue looking at this
its okay
20, 28, 28, 32, 32, 32, 36, 36, 36, 44, 44. 44, 48, 48, 48, 48, 52, 52, 52, 56, 56, 60, 60, 64, 64, 64, 68, 72, 72, 76, 80, 84, 84
cf = 33
i fixed it
@hybrid sage 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.
this is gonna sound completely stupid, and i know this is more data sci but idk whhere elsr to ask, but if i have a bunch of data points as shown above, how would i get the x coord at which the straight line becomes now a line with a gradient.?
uh, do you mean roughly
as in if you drew a curve of best fit, the point when it stops being "basically straight" and starts being "basically curved down"?
Yea would have to be roughly
i dont want to just eye it as it would be cheating
and I assume you want more than just eyeballing it
even though trhat would be pretty easy
yeah okay
fit a quadratic (or other) curve to the data, get the equation
differentiate it, solve for when the gradient becomes sufficiently negative (i.e. it's curving down enough to be "actually decreasing")
Yea that could work
thanks
but like
there is so much noise
how would i fit a curve to that data
honestly I would just not bother with that last step - fit a curve and eyeball it
choosing a threshold as to when you deem it sufficiently "curved" is eyeballing anyway
yes
which is way out of my grade
are we talking, excel/google sheets level of paygrade here haha
because you just want a (quadratic) regression
wym, like where this data came from?
as in yes, how do you have this data
or can excel do stuff like this
yes
for my physics project, atomic microscope needle and voltage stuff
its for my undergad bsc
so pretty mathy
curve of best fit in excel or quadratic regression in scipy
yeah, it'd be better (for academic project purposes) to do this thoroughly
Yea
thats also why ML is out of my range like i probably could learn not worth the effort though
yeah I'm suggesting reaching for "ML" in teh very simple sense - regression curves
no need to train anything or w/e
fit the curve with scipy, calculate the x values that are deemed sufficientyl curved for a range of threshold values, and then report your findings as that interval in some way. makes it more mathy than just "I picked this gradient because idk"
for my group project
even better.
you know more than me, go for it
Closed by @stable halo
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 ideas?
do u know ur double angle for cos? @molten bay
we’re gonna wanna use u-sub to make it simpler
what form of double angle would allow for a simpler du? @molten bay
@molten bay Has your question been resolved?
Closed by @molten bay
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Let $a_1, a_2\ldots a_n$ be a strictly increasing sequence such that $a_n>0$ and $a_{2n}=a_n+n$. It is known that if $a_n$ is prime, then $n$ is prime. Find, with proof, the value of $a_{1993}$.
;(
!status
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
1
Literally all I know is that a_0 is 0
a_2=a_1+1 is prime so that means a_1 is composite
Literally nothing else
the condition a_2n = a_n + n combined with the fact that the sequence is strongly increasing is very limiting
how do you know that a_2 is prime
That’s the problem
I don’t know if I can use the converse or not
.
it heavily restricts the possibilites of what a_n could be
what does it say about a_2, a_3, a_4
ah wait I assumed that the a_ns are integers
I suppose thats not given
Nope
well they probably fucked up when writing the problem
Figured out that a_n=n+c is a general solution
Wait nevermind lol
It says positive integers
surprise
Valid?
yes
I’m in class so I can probably explore this
I’ll come back in god knows how long
I have a lab to do
(a_0 doesnt even exist)
is a0 even defined?
Yeah
Aight I think my brain is fried but I got it
I think a_n=n is a solution anyways
If a_n is prime then n is prime
So a_{1993}=1993
Bruh gg
a_2n = 2n+c, an+n = n+c+n
that’s so true actually
you can easily disprove this, the statement says if n is prime then an is prime, put n = 3 you get a3 = some even number.
oops, but i think you can find a non prime n for which an becomes prime
@dusty portal 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.
Let f: AB -> CD be the projection of points in AB to CD
Let x be the point where pojections are made in AB, for each point x in AB we can draw a line to CD which intersects a unique point Y.
Thus we have f(x) = y. this is one to one since if we have x1 and x2, and they mapped to the same y on CD then the projection would make no sesnse. this is also onto since all points in AB will project to CD. Therefore this is a bijective mapping
did i answer this? lol
@warm island Has your question been resolved?
projected how? if you just draw a line from AB straight down to CD, f is not onto
since the length of CD is larger than the length of AB
@warm island Has your question been resolved?
Yeah you make a good point
I'm guessing there's some sort of relationship I can make idk
you can actually pretty easily make a linear relationship between the two.
if you assume x goes from 0 to L and y goes from 0 to M (with L < M) construct the line that goes from (0,0) to (L,M)
alright ill think about it im doing this just for fun '
@warm island 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.
Totally stuped on this problem from Real Analysis. I've got two vectors x and y, both in R^n. I've got an affine function Ax+b, with some matrix A and bias vector b that I don't know. I'm supposed to optimze A and b so that | |y-(Ax+b)| |^2 is minimized. I've got no clue how to do this. I don't know how to differentiate with respect to a vector or a matrix. Need some direction on what I'm supposed to be doing here. Book is useless and I don't want to spend 2 days barking up the wrong tree researching this.
no
Well
If you get to choose A and b
Choose A so that Ax=y has a solution and let b be the zero vector
Then it's minimized
I assume that that's not the intention of the question though, so what do you mean "optimize A and b"?
the extrema of f(x)=||y-(Ax+b)||^2
will have grad f (x) =0
aswell
@true egret Has your question been resolved?
What they literally ask is "find the affine function g(x)=ax+b such that the sum (j ranging from 1 to the number of dimensions) of (y_i-g(x_j))^2 is minimzed." I think that's equivalent to minimizing | | y-(Ax+b) | | ^2
But then it's such a stupid question... that can't be what they're fishing for
I don't know how to take the gradient of a function that has a matrix in it
@true egret Has your question been resolved?
@true egret Has your question been resolved?
you can use linear algebra to solve this
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.
One message removed from a suspended account.
One message removed from a suspended account.
One message removed from a suspended account.
you want to add up $\sqrt{dx^2 + dy^2} = \sqrt{1 + (dy/dx)^2} \sqrt{dx^2}$ and $\sqrt{dx^2} = dx$
south
One message removed from a suspended account.
,w derivative of 2x^(5/4) wrt x
that's not what the arc length formula says
yes you should be doing sqrt(1 + (y')^2) instead
One message removed from a suspended account.
One message removed from a suspended account.
yes and then try taking sqrt(1/4) = 1/2 out of the square root
One message removed from a suspended account.
so $\sqrt{ \frac{4 + 25 x^{1/2}}{4} } \cdots$
south
One message removed from a suspended account.
One message removed from a suspended account.
write 1 = 4/4
One message removed from a suspended account.
One message removed from a suspended account.
yeah if it's more natural to you, you can multiply the square root by sqrt(4) = 2, then divide by 2 on the outside
^ this is how I would do it
One message removed from a suspended account.
One message removed from a suspended account.
One message removed from a suspended account.
Closed by @upbeat plinth
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.
Ik one of the factors is (x-1)
But idk if I gotta find a new other one to know what to divide this by or what I do from here
If you haven't been taught any methods to solve a cubic then you have to find another factor
Alr ty
yes the technique is always to divide by linear factors until you get a quadratic
except if you can spot if the cubic is a perfect cube or some other special case, mainly that and a^3 + b^3 or a^3 - b^3
We were not taught that
don't worry if you can't spot these special cases though
So prob shouldn't do on exam
p stands for polynomial!
Fancy
Ig that makes sense 💀
cause of the alphabet haha
Yeah 💀
Idk
I did one of these questions to study
Got it first try
Idk if I wanna do more
For this 7a
Would I just set x has 2
And make it = 0
The remainder theorem I think it's called
correct!
so that's actually called the factor theorem, but that's just the remainder theorem with remainder = 0
Ok
Another question actually
For 11
Would I just start by diving by -6
Theater that factor it
To get my other 2 factors
Which is the L and W
,calc (-6)^3 + 14(-6)^2 + 63(-6) + 90
Result:
0
yes so you would need to divide the polynomial by x - (-6)
or x + 6
np!!
but will that result is zero right ?
yeah like just making sure the question wasn't broken
I know that it has x + 6 already
oh okay
Math fun
When you actually understand it
But I also hate studying late
So idk
But Ty guys
it's about the journey not the goal bro
just enjoy when things getting hard that what i mean
and the best times is when getting the answer
if you don't need the channel to forget to close it @steep mirage
don't*
Actually
Got 1 more thing 💀
How do you find the multiplicity
Wtf is multiplicity
Can someone give an example
bro try to revisit the lesson first 💀
I did
But no where does it say how you find the multiplicity
My teachers notes suck ass
I was gone at an appointment
i see
i'am in a middle of a session i will finish it and try to figure it out with you
Actually
can i ask smth personal tho
Do you just simply look at it to find the multiplicity
u are at g12 right
I just don't understand how you find the multiplicity when you aren't given a picture
11, but this is a grade 12 course
yeah because of that i see these questions in my Papers
is that SAT or just regular school work /
Regular
Test tmr
This is the hardest math class my school offers
And it ain't even bad
oh bad situation you in bro
Nah it'll be aight
lol that's a regular shit in my SAT Course
without so much yapping im gonna finish quickly and try to solve it with you
@steep mirage 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.
im sorry- what does that mean?
like using x measured in radians??
nvm im freaking dumb
.close
Closed by @median ridge
Use .reopen if this was a mistake.
yes it's not true in degrees or any other unit
i mean degrees isnt really like a proper thing i'd say
like that sounds weird
but if u think of it with the unit circle, it makes no sense to use degrees
degree and radian are unitless
exactly radians are the natural units for all trig functions
correct so more like natural conversion factor
.reopen
✅
not unitless but dimensionless
am i supposed to be imagining a graph here or is it just an expression?
both
well the graph of (sin x)/x is pretty tricky
if its the graph of it, it makes me confused but expression wise is different
what do you mean by expression wise
look idk
but with the graph, there is a point where x = 0
which is 0/0 but its still there in an actual graph so it confuses me to use radians
because x = pi is an actual point on the graph
Actually, there is a hole at (0,1)
I mean, at x=0 function is not defined
obviously i can scroll forever but shouldnt there be a more obvious circle to show that theres a hole there?
Desmos isn't very good at that unfortunately
if you hold and click on the graph at exactly x = 0
Loll
truee
oh okay
i get it now thank you
do you think it was kinda a bad example to use orrr?
no!
it's really good you're thinking about limits and how that differs from if a function is defined at that point or not
that was the whole point of your original message
what your textbook or notes wrote there
okay
they put a photo of the graph below but i still wouldve liked to see a hole lmao
.close
Closed by @median ridge
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.
Expand a^x.
As a sum of powers of a.
Give us an example
!xy
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.
Let a = 5.
We need to expand 5^x.
Let 5^x = k
Then (k - 1)/(a - 1) = 1 + a + a^2 + a^3 + ........... + a^(x-1)
where k = 5
a - 1 = 4
(k-1) = 4 + 4a + 4a^2 + 4a^3 + 4a^4.................... + 4a^(x-1)
k = 5 + 4 * 5^1 + 4 * 5^2 + 4 * 5^3 + 4 * 5^4.............. + 4 * 5^(x-1)
So 5^x = 5 + 4 * 5^1 + 4 * 5^2 + 4 * 5^3 + 4 * 5^4.............. + 4 * 5^(x-1)
he truly did if you ask it it it also gives this weird line of reasoning of a-1 expansions
I guess one can find 5^x from 5^(x-1)
Ok so do you want to write the expansion of a^x using the geometric sum formula?
No
That's exactly what u did
It's useless
!status quo
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
!done
If you are done with this channel, please mark your problem as solved by typing .close
Closed by @prime garden
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.
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 dont get part i like how do you start
hmm
probably use the fact that $\sin^2 u = \frac{1 - \cos 2u}{2}$
[ \f{\sin a + \sin b}{2} \geq \sqrt{\sin a \sin b} ]
on a restricted domain
oml it rearranges to that? cool
.
ah I know ok let's stop here and let them think then'
this probably works
nah your idea's better
ah but you need to be careful cause sin a, sin b need to be nonnegative here
.
the way to fix that is to use the rearrangement, $(\sin a + \sin b)^2 \ge 4 \sin a \sin b$
south
yeah then Jensen's or something
neon
Wait whats that
Jensen's inequality, go search it up
it's useful for situations like this where you want to compare f(x + y) and f(x) + f(y)
Idk whats going on in that 😭
Closed by @empty ivy
Use .reopen if this was a mistake.
you can go ahead and try to apply Jensen's but I think that is an overkill, you can start from here and prove 1 from algebraic manipulation and then prove 2 from 1 and some more inequalities manipulation
(I feel this is the expected solution)
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 graph this?
q3?
q2
break it into 2 pieces, and differentiate each piece
well it has a straight part and a parabola part, right
yes
so the gradient for the straight part would be...
dr du
💔 yeah
yr 11?
yeah
prolly not if im struggling on this
u got this gng
😭
Find the equation for the straight line graph and the parabola separately
do i need the equation
or can i do with just like points
how will you do it with just points
no idea
how will you so it with equation
also no idea
so you can find the eqn of the parabola and differentiate it
yeah
and then the derivative is 2x - 2
huh
basically the line and parabola
um
did you find slope of the straight line
do i put open circle at -2
or closed
dont think about that for now, first plot the graph of derivative of parabola
is it just a straight line 2x-2
yes
would this be right
plot y = 2x - 2 from x=-2 to x=infinity
o
should be open
whats the curve called when its like all wiggly
wdym by that
that's the graph for a cubic function
What is a stationary point
1,0
You’re question is for part a right?
both a and b
prove that the stationary point of infelction is at x=1
In reference to the graph
You need to justify the fact that the the stationary point is actually a stationary by referencing the graph
So you need to consider the gradient function’s behaviour at the point (1,0)
And link that to the graph
Therefore
since the parabola is concave down its maximum turning point is at 1,0 and since the gradient at 1,0 is 0 its also a stationary point
?
Pretty much yeah
You talking about b?
yes
Consider the derivative right
We know it’s going to be an increasing function up until the stationary point then it’s gonna start decreasing
Wait nvm the derivative is constantly negative right?
So how do you think the original graph is going to look like?
isnt the original grpah the one they gave?
No that’s the derivative of the original
It’s negative so the values of the original function are always going down right?
yes
Ok and we know that the original function has the value -3 at 1
yes
We know that the derivative is quadratic, so what type of function must the original be?
Right but what type of polynomial
It’s a cubic function
The graph that you said was all wiggly
Since we know that the original is cubic and it has the point of inflection at that point.
Also it’s constantly decreasing you can put these together to make a sketch of the graph
😭
What do you not understand?
Yes since it’s the only stationary point
You know what a point of inflection is right?
its like
where the concavity changes
so would i draw it
from the top left
and then it passes through
1,0
and hten to the bottom right
This is all right though
You have the answer
Yeah, the slopes aren’t that steep but since it’s a sketch it’s fine
okay
how do i determine the nature of a stationary point?
You need to look at the second derivative or take values of the derivative of either side of the stationary point
well
i did the 2nd derivative
and i have the x values of the stationary points
what do i do now
okay
I don't think that last one is correct
The one for stationary inflection points
Oh right, if it’s zero it doesn’t necessarily mean it’s a inflection point
Yea it's inconclusive
Then you'd have to use the first derivative test
@novel dune Has your question been resolved?
no
Sorry I am a bit busy as I have a test in like 45 mins
which one
q1
hmm you'll have to look up that first
because that's how you'll get the values of x
no no that's not how you solve these
so draw a number line
yes
yeah
yes
yeah so plot -2, -1 and 2 on the number line
this whole thing is positive
yes
yes
@novel dune Has your question been resolved?
Sorry I had to go lol
You can try it yourself first
Then we can cross check
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't we have well defined functions which are not expressible as a expression but instead is better found in other ways
an expression*
$\int_0^x e^{-t^2}\dd{t}$
Ann
famously this integral is not expressible via elementary functions of x
Has it been proved? Proved that it's not possible?
But it's still expressed as an integral right? But like functions which are descriptive in english
But can't be expressed using any symbols whatsoever without actually making like a lot of cases
In symbolic computation, the Risch algorithm is a method of indefinite integration used in some computer algebra systems to find antiderivatives. It is named after the American mathematician Robert Henry Risch, a specialist in computer algebra who developed it in 1968.
The algorithm transforms the problem of integration into a problem in algebra...
seems so
tho i have not looked into it
Ok
"can't be expressed using any symbols whatsoever" is a tall order!
give an example
Hmm makes sense! But what about like what if we want to know if we can go from input to output always
Given input and a description of the function
How to find output
@stoic garnet Has your question been resolved?
Closed by @stoic garnet
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 could i do this on a calculator?
R_3 is just for n = 3
you can easily compute it using 3 subintervals
but regardless, can u shwo the whole question?
u may not have to use a calculator at all
this is the whole question
oh sorry
idk my test is with calc so i thought i might as well as try to use it to the best of my ability
ik its an overestimate
bc its a right riemann sum
and because it is increasing
ig itd be 13.133?
nah use calculator for that
how tho
yeah we're not allowed to use any other calculator
uhh
u compute that from k = 1 to 3
so u just add (f(a+deltax)+f(a+2deltax)+f(a+3deltax))deltax
a being lower bound, delta x being (b-a)/3
do u know what riemann sums are?
do u know how to convert that integral to its riemann sum?
[\int_{a}^{b} f(x)dx =\lim_{n \to \infty } \sum_{i=1}^{n} f(x_i)\Delta x ] where (\Delta x =\frac{b-a}{n} ,x_i=a+i\Delta x)
HeavensJester
oh
ok so the definition i get
now how to plug into a calculator to actualy solve though?
use as approximation like instead of n \to \infty let like n=1000 or something
nvm i just put it into plot graph
and did it from there
i think doing summation is just overcomplicating it
so something like [\sum_{i=1}^{1000} f\left(a+ i\cdot\left(\frac{b-a}{1000}\right)\right) \frac{b-a}{1000} ]
HeavensJester
Closed by @spark gazelle
Use .reopen if this was a mistake.
not really in your case let the 1000(I chose 1000 as it would be a better approximation for the actual integral) be 3 as the
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 know how to approach this
i mean
one would assume the numerator factors out
,wolf give factors of (3x^5 - x^4 + 2x^3 -12x^2 -2x +1)
this seems like you need to decompose it to simple fractions
start by factoring the denominator for that
you can start with (x^3-1) = (x-1)(x^2+x+1), so you'll have 4 fractions
@lament fox Has your question been resolved?
that would be a gnarly partial fraction decomposition no?
so?
,w (3x^5-x^4+2x^3-12x^2-2x+1)/(x^3-1)
C'mon, I need the quotient and remainder
,w quotient and remainder of (3x^5-x^4+2x^3-12x^2-2x+1)/(x^3-1)
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.
• 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 $a$ be a real number satisfying $\$
img
If the set of possible values of $a$ is $(x,y]$ for real numbers $x,y$. What is the value of y - x? (correct to 4 decimal places.)
Copter
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
can someone help me? i have no idea where to begin
please dear math gods, bless me with thee knowledge😭
i dont understand what the question means
the latex is weird too
Hints:
- 2009-1=2008
- 2552-1=2551
- 2008+2551=4559
find the set of real number a that satisfies the equation, probably
Yeah that’s the interpretation that I went with
yeah i did notice that...
im not good with this type of stuff xd
._. Why didn’t you say that then
But what can you conclude about the floors (as in what are their values)
a>1?
I’m asking about the values of these
mhm
Yup
aaa ive never done this😭
2009 > 2009/a >= 2008, maybe?
YIPPE
give me a moment
1 < a <= 2552/2551
,w 2552/2551
.
,calc 2552/2551
Result:
1.000392003136
so the answer is 0.0004
Mhm
Closed by @chilly cobalt
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 can i get help
arcsine(0.59)
your calculator should have a button that says sin^-1 or something similar.
oh yeah
use it to calculate $\sin^{-1}(0.59)$.
Ann
this will give one answer
and also make sure the calculator is in degree mode.
its asking for 2 answers tho
do what i said first. that's going to be your part a.
ok i gt 36.1570082
!15m also
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.
round to nearest whole.
36
i used it once
right
look at the graph now and see that it crosses the line y=0.59 in two points
one of them is the x=36° you just found
thats gotta be the one closer to 0
the other is symmetric to it across the line x=90°
in other words the other solution will be 180-36
sin(180°-x) = sin(x) always
alr
@ruby willow Has your question been resolved?
Closed by @ruby willow
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 why my logic is wrong when I see, integral of cosx/sinx
im not sure if i aksed this before bc i forget but i js did integral of (tanx)^-1
but this doesn't get the right ans of ln|sinx| + C
cuz integral of tanx^-1 is js ln|tanx| * (secx)^2 + C i think
the correct way is to use u sub which i realize now
but why is this way wrong?
im aware it gives me the deriv as 1/ sinxcosx which is obv not cosx/sinx
but i still dont see what is wrong with converting cosx/sinx to (tanx)^-1
even this is wrong acc in case i didn't make that clear
why not just do a substitution
no like ik you can
but the first time i did this question i didn't
so like im js not sure what is wrong with the method
well u do get cotx, but thats just overcomplicating sum trivial
ok but integral of cotx and tanx^-1 is diff tho
like the method i mean
not the ans
well tan^-1 is arctan. if u mean 1/tanx, then thats cotx
well yea ud needa sub and then u get ugly stuff
yeah but like can u show me how to do it that way anyway 😭😭
im kind of confused on what to do after i get integral of tanx^-1
can you send your work
ok lemme get sum paper, im rusty on integrals
i js wrote
$ln|tanx|\cdot\frac{1}{cos^2{x}} +C$
gamer75431
which im not sure if thats right
i js know that when you differentiate this you dont get cosx/sinx
i can tell you where you went wrong
ok well i ended up after sub u=tanx with integral du/u(1-u^2)
ah u cant apply ln to that
it needs linear function on bottom
ln doesn't apply to trig func?
nope
oh
integral of 1/tanx dosent work like that
onlt integrak of 1/x i lnx
only*
ohh
oh okk
yeah but just u sub there
well yea but u can skip that
yeah
deriv of ax+b is a
no sorry i forgot to type it right lmao
wdym
like is this wrong?
