#help-10
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How do you find the probabilities of 2 events
that happen back to back
say you roll a 6 twice in a row.
what are the probability of that happening
1/6 x1/6
were not given any value for the first coloum tho
The first column is given to be a bus
wdym
I defined the columns to be like this
ohhh ok
so what do we do from here
did they do 1-.4 to work out bus
but that dosent make sense
Lets define
P(B) as the probability that Jean takes the bus
P(T) as the probability that Jean takes a taxi
So if Jean takes the bus on monday, the probability she takes a taxi on tuesday is 0.4
yh
and the bus is 0.7
on monday its .7?
The probability of her taking the same mode of transport the next day day would be
P(B|B) = 1 - P(T|B) = 1 - 0.4 = 0.6
P(T∣T)=1−P(B∣T)=1−0.7=0.3
To find the probability that Jean takes a taxi on Wednesday, we need to consider all possible paths she could take from Monday to Wednesday:
which are what
Monday is always the bus so
TB and BT
Monday (Bus) -> Tuesday (Bus) -> Wednesday (Taxi)
Monday (Bus) -> Tuesday (Taxi) -> Wednesday (Taxi))
k i understand this bit
So now we need to compute the probabilities for these paths
still not sure on this bit
isnt P(B|B) = P(B n B)/P(B)
oh u worked that out
mb
soz for interupting
ok so getting back to computing the probabilities
i wrote it in python to be cool and i can explain the steps easier
First path
P(B) * P(B|B) * P(T|B) = 1 * 0.6 * 0.4
P(B) * P(T|B) * P (T|T) = 1 * 0.4 * 0.3
# Given probabilities
P_TB = 0.4 # Probability that she takes a taxi after taking a bus
P_BT = 0.7 # Probability that she takes a bus after taking a taxi
# Probabilities of taking the same transport the next day
P_BB = 1 - P_TB # Probability of taking a bus after taking a bus
P_TT = 1 - P_BT # Probability of taking a taxi after taking a taxi
# Probabilities for each path to take a taxi on Wednesday
# Path 1: Bus -> Bus -> Taxi
path1 = P_BB * P_TB
# Path 2: Bus -> Taxi -> Taxi
path2 = P_TB * P_TT
# Total probability for taking a taxi on Wednesday
total_probability_taxi_wednesday = path1 + path2
print(total_probability_taxi_wednesday)
Comes out to 0.36
ok so how do we work out the .6 and .4
thats the bit im confused to workuing out
the notation im using is kind of off but
P(B) represents monday.
The probability of her taking the bus
Which is 1 because its given.
P(B|B) is the probability of Jean taking the bus on the second day after taking the bus
Which is 0.6 as seen in the chart
the chart is from the markscheme
that in the anwser not in the question
how did u work it out to be .6 on tuesday
If she takes the bus on the first day, the problem reveals that the probability of the taxi ride on the second day is 0.4
So the bus ride is 1-0.4
Which is 0.6
shit happens I've been running on a quarter of my brain power for the past week
if you wouldve asked me this yesterday i wouldve been STUMPED
lool
btw u mentioned python are u in university?
comp sci
well comp sci rn gonna be taking engineering once i finish this degree and some other shit next year
yh i applyed for comp sci for uni
complicated
but at school the most ive done is effectively high-school level math...
dayum
apparently comp sci is kinda getting saturated
that what im worried about
i kinda wanna switch to maths for uni
last year was bad but the job market is slowly recovering
ive been considering this aswell
maybe a math teacher or something
alright
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Why is the answer x - 1 and not 1 - x ?
maybe because when it's squared it doesn't matter?
(1-x)^2=(x-1)^2 yeah
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hello guys
this is the first time for me asking help from here
however, what are the advanced algebra tricks to solve limit, I mean sometime the limit is very complicated, and don't know how to start it?
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Plainly, I don't even know where to start.
I think it has something to do with the standard error of the mean (2.214 I think)
If someone could point me in the right direction, that would be great
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Hello i just have some questions regarding derivatives as someone just looking into it for fun
so don’t get mad if i don’t fully have a deep understanding of the concept
ofc
but i don’t understand how you get the slope from a given point
Slope is a measurement between points
There is no slope of a point
The derivative try’s to measure what would be, if it existed
it is generally known as Difference in y over Difference in x
Do you know the definition of the derivative using the difference quotient?
so it can never get to a singular point
no, i don’t really have a definition i just understand the concept
its just that the difference gets extremely small
Didn’t you just say you didn’t understand the concept and that’s why you’re asking this question?
Look at the definition
It will help you understand the concept
can you tell me how i would graph a visualization on desmos?
wait so is a derivative also a function?
Sometimes
or ig something i can shove numbers into and get something out of it
Sometimes
There is a video series on youtube by 3blue1brown which is very good for beginners and visualises everything needed. here's a link: https://youtube.com/playlist?list=PLZHQObOWTQDMsr9K-rj53DwVRMYO3t5Yr&si=0fNoQ5PUEozJNAOy
thank you
watching this will clear up a lot of your questions
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im trying to use the alternating series test for this but one of the requirements is that bn is decreasing on the interval but the problem is that its actually not decreasing from 1 to 2?
so like what do i do
b_n is decreasing on what interval?
Show that your series is absolutely convergent, and then it follows that it converges, that's all.
so should i just ratio test it
for convergence, it only matters what's happening "eventually"
oh ok
no, please use comaprison test for absolute value of the geenral term
it doesn't matter what's happening for the first finitely many terms
so you mean if absolute value of the series converges then its absolute convergence
and if it doesnt then its conditional?
yes, if absolute value series is convergent then yours is absolutely convergent hence convergent
yes thats what i did
write in a such way
then 1/n^2 is very knwon seris convergent harmonic of an order p =2
so veryone accepts it
yes
hence your series given oen is absolutely convegeent, and then
it implies convegrence
no need to mention about conditonal convergence here
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so i been stuck on this for the past hour
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if it's on computer, take a screenshot, if it's a problem in a book, you can take a photo?
its more of the work i got like 3 pages of messy notes XD
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hmm
i solve for dv/dt first
and get roughly dv/dt = 9.81-1/3 v(t) then im suppose to solve for v(t) and it shows me some expnential and idk how to get to that
what do you mean it shows you some exponential
there is like a example problem to show you the steps
but idk what it does to go from that
it is a differential equation
to v(t) = 32.7-32.7e^ (-(3t/10))
do you know about differential equations? specifically first order linear nonhomogeneous diffeqs
not the same numbers but looks simmiliar
and tbh yes but my brain is fried and i keep getting an answer like only off by .7 or so at the end
and yee ya take the integrating factor by getting integral of pxdx to e
okie dokie gimme a min to re write it to not be a complete mess lmao
yeaaa im lost lmao
tried reworking it
and just following their problem
dv/dt = 9.81-3/10 v(t)
says use separation of variables to determine velocity equation
and they get v(t) =32.7-32.7e^ (- 3t/10)
also not helpfull that this problem has 19 parts in the view an example 😭
dv/dt = 9.81-3/10 v(t) idk how to go from this to v(t) =32.7-32.7e^ (- 3t/10) like i understand the concept of e ^ intergral pxdx = u and v(t) = 1/u integral u qx dx
but i got no clue how to actually do that here
i would appreciate if you showed a picture
@pastel lichen Has your question been resolved?
<@&286206848099549185> can someone show me how to work this out
like better than the example lol
@pastel lichen Has your question been resolved?
maximo
we let
[\mu(t) = \text{exp}\left(\int \frac{3}{10},\dd t\right) = e^{\frac{3}{10}t}]
maximo
and then we can write the diffeq as
[\dv{}{t} \left[v(t)\cdot e^{\frac{3}{10}t}\right] = e^{\frac{3}{10}t} \cdot 9.81]
maximo
@pastel lichen if this is not obvious let me know, but it is just part of the method for first order linear equations
where does the 32 come from ?
what 32
if you are talking about the answer
i am not there yet
so i have no idea
this part
i am working this question out for your benefit
actually i'll let you integrate and find out where the 32 comes from
go from here
not sure aint e to anything just e
i honestly dont know ima just take the l for this homework problem
no
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I need help learning right triangles and trig
!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
I missed like 4 days and she gave me a quiz and got a 3.5/18 now i need to do correctins
Do you have any work you want help with?
ask your question
practice
and open help channel if you have a problem you stuck on
so i got this triangle
its a right triangle
45-45-90
i only have hyp
whcih is 10
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use the (1, 2) point, plug in 1 for x and 2 for y
(and now that you know a, plug in 5 for a)
so 5 times 2^(2)(1)
hm wait wait why are you putting a 2 in the exponent there?
yep so 2 = (5)2^b do you know how solve this for b now?
would i log it?
yeah exactly but start off by dividing by 5 on both sides first to just ahve the 2^b isolated on one side, then log as you say
so 2/5=2^b
yep, now time to log, which base should the log be?
10
you need the same base as the exponenial part youre trying to reverse (2^b) so base 2
b=log2(2/5)
assuming you're writing a base 2 log there, yes correct
$b=\log_2(2/5)$
Soosh
how do you think i should input this since we are not suppose to enter log but a number
well if you wanna estimate it on a calculator, you can use a change of bases thing since most calculators will only do base 10 or natural base (e)
so to write it in terms of a new base c (say we want 10), it would end up as:
$\frac{log_{10}(2/5)}{\log_{10}(2)}$
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Soosh
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@obtuse raven Has your question been resolved?
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help anyone??
note: $\sqrt a \cdot \sqrt b = \sqrt {ab}$
ren
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How did you find the root?
You can use rational root theorem
whats that
The rational root theorem (rational zero theorem) is used to find the rational roots of a polynomial function. By this theorem, the rational zeros of a polynomial are of the form p/q where p and q are the coefficients of the constant and leading coefficient.
thats really long lol
ColdTee
n = 3
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How can I find the exterior angle of a shape?
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send question
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Hey
I need help with this question
f(x) = 0.5 (x-4)² - 2
As well as 3x² + 2x - 8 = 0
what's the question
One sec
Determine the vertex and the direction of opening for cach quadrau
function. Then state the number of zeros.
you can find vertex of the second equation by doing -b/2a, to get the x value of the vertex, then plug that into the equation to get the y value.
openings depend on the "a" part, if "a" is positive it opens up and if it is negative it opens down.
I need help
i'm doing the same stuff in math rn lol
U think u can write it down?
10
I'm in grade 11 studying rn for a quiz
I forgot what I did since grade 10
no worries
basically
you're familiar with ax^2 + bx + c = 0 right
@haughty hamlet
Yea ofc
yeah hold up
k ty
working on it
Ok thanks
do you know what factoring is
Yea
can you factor the equation 3x^2 + 2x -8
Yea
what is it
i don't think you can factor it unfortunately
Alr
you just need to remember
the vertex is a coordinate, and the x-value is always -b/2a in a question like that
then when you have that x value you plug it in for x in the equation and you get your y value
also since it's just asking you how many x intercepts (or zeroes) there are, you can put two
this is the graph for the equation, it crosses the x-axis two times, therefore there are 2 zeroes.
Yeah I understand that part
here's the second equation hope this helped
vertex is always (h,k) in that type of equation
in "a(x-h)^2 - k"
That does that say?
The last part
Something opens up
So?
A = 0 . S, which is positive so it opens up?
Correct?
@timid silo
0.5
sorry my handwriting is bad
it says since a = 0.5, and it is positive, it opens up
basically whenever "a" is positive it opens up, when it is negative the graph opens down
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Yes sir
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I don’t understand this, this is theorem 4.
What is really the central angle here??
It's the angle formed at the center when end points of the arc are joined to the center
Ig an angle formed at the centre
like with the centre as the corner
cuz there are infinitely many possible central angles
cuz the the end points can be any two points on the circle
wth
that's complicated
what if the question was "Find MTP" what's the central angle for it?
i mean u can define a unique central angle for a given pair of points lying ON the circle
oh how
so the central angle here would be MAP?
u can in technical terms say it's the angle subtended by 2 points at the centre
i mean u mentioned 3 points so if u consider central angle for M and P, it's MAP
oohhh and then what about the intercepted arc? is it the looking for ? like "find MT" will it be like "MAT is the central angle and MT is the arc intercepted by the central angle" ?
yup
what do u want to compute
oh the arc length?
u need to know the radius for that ig
hmm I wanna compute the " find m TP "
Could u tell me what u mean by that notation? cuz i noticed u wrote an angle as the answer
are u referring to the central angle of those 2 points or the arc length?
radians are degree right
not really
oh.
2pir?
so considering the central angle is say x
we get (x/360) * 2 pi r as the arc length
mb xD
pi??? as in 3.14??
yeah
cuz what fraction of the perimeter is the arc length?
x/360 r8?
taking angles in degrees
Help my teacher doesn't apply that in our lesson tho..
😞😓😓
its like you just minus and add here
uh i think ur teacher wants the central angle then maybe?
as far as ik the m MT isn't a 'standard' notation, but i'm checking right now to be sure
ok so like im finding m TP here
yeah but is m TP the length of TP or the angle subtended by T and P at the centre?
whaaaaatt !! T-T
uh what grade r u in?
10th help
oh okay
um if m TP means the length of TP, u need to find what fraction of the perimeter TP is
does that make sense?
yeah but why fraction
um cuz or else how will u find the arc length?
by degrees?
like we know how to find the perimeter
so the arc length is some fraction of the perimeter
uh that's the angular length then
so the central angle of the 2 points
mhm
145+35?
yup
yeah
can u elaborate?
ah
its nothing
Im so sleepy i cant comprehend anything anymore
thank you so much btw !!
my pleasure man o7
it's ok dw if u get confused
oh dw it'll be fine
HWAKLDKSALDJ I hope so
just remember to visually understand the problems
all the best for ur test o7
u should close this if ur done
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mplicit differentiation of x^2y=y-7
im stuck at 2xy+x^2y'=y'
what's your issue with solving for y' here
i dont know what to do after
after you've isolated y', nothing, ur done
are you solving for y' ?
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Exercise from my Topology and Metrics lecture notes that I am trying to prove. My idea is to show that there exists an N such that K_n \subset U_0 for every n > N and thus that all by finitely many K_N are covered by U_0, and thus construct the rest of the finite cover by taking the covers of the finite number of remaining K_n, but cannot seem to prove that, presumably because it is false?
alternative directions are to show closed and bounded, or sequential compactness, though I have had no success in these avenues either.
<@&286206848099549185>
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AB is the chord the length of the chord is the same as a inscribed triangle what is the area of AOB if AB is 5
u mean its an equilateral triangle?
wdym by the length of AB being the same as an inscribed triangle?
Yes
Not prove it this triangle is not inscribed
As you see
The inscribed triangle is not in the drawing
could u plz restate the proble,
It’s just a formula
You an go slower if you wants to
The result remains the same
@hoary idol
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I'm confused, not sure where to start.
the augmented matrix
as in [4.5, 3.1 = 19.249]
[1.6, 1.1 = 6.843]
and then row reduce that?
understood
so
then what is w1
will it be the row reduced matrix of the augmented?
i dont know what w1 is
again, i dont know what w1 is
w1 is the solution to the system
alright, when you row reduce
if you get the left two columns to be the identity matrix then the last column is w1
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How did they get that?
Oh they used the previous result
Imo, wikipedia has a much cleaner derivation of this fact:
Actually, this only really works for random variables, which might not work here. Nvm, ignore me
Oh
So there’s no simpler way?
I have to just memorize the formula because it’s unlikely im going to be able to derive this whole thing during a test
I guess if you think of E[X] as "mean of the data set X" and recognize that E[A + B] = E[A] + E[B], then the above still works
I find that notation really confusing
Basically, Var(X) = (mean of X²) - (mean of X)²
Where X is a data set, and X² is the same data set, except all points are squared
Is a generally easier way to think of variance
Oh
Okay
I’ll try to keep that in mind
Thank you
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How would you solve this?
I’m forgetting how to do this
you type 13 as follows: 13
😁
or, if you really want to know how to do it, try factoring the numerator
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idk how to do this tho
then do this
ok nevermind that
i need help with 9 then 8
but
i got 10,8 for 9
this is for 9
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Could anyone explain this?
this is a ED separable
so you can put all Y or in this case m(x) and the X on the other
And integrating infinitely small x (dx) gives me simply an integral of 1?
on the left you see a dx standing alone after integrating $\int_{.}^.{1dx}=x$
nico
$\frac{dm(x)}{dx}=\sqrt{...}\
\frac{dm}{\sqrt{...}}=1dx$
nico
So what this dx means is solely an indicator that the integral if calculated in respect to x?
Ok, it makes sense. Thank you
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Hello!
hellooo!
Can someone let me know whether or not I’m doing this right?
unfortunately no
the hypotenuse of the triangle is a straight line
since width and length are the axes, straight lines are described by something like
length = (slope) * width + (y-intercept)
So I put it in the formula y=mx+b?
Actually that’s definitely not 65
65 is the correct y-intercept
Really??
Is the slope 1?
Nvm
It’s not
I know it’s less than one, but I don’t know how to decipher the numbers less than one on the graph
-5/5?
-5 / 5 = -1 is the slope yes
Nice, so it’s
(less than or equal to) -1 + 65?
I know that’s not the whole inequality
where did your x go
But so far?
use this
Wait yeah it’s c
X=-1w+65?
Wait no
It’s mx
<@&286206848099549185>
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I need someone to explain why those are the answers
A means always, S means sometimes, and N means never
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is there an easier way to do this other than by inspection like the example from the textbook?
also, extend to form a basis means you have to keep these original vectors still right?
I tried turning each vector in S to form columns in a matrix.. and then see if its linearly dependent
if it is thats means I still gotta get rid of a vector
but Im still taking out the unnecessary vectors out by inspection...
Also, this is an example that is unrelated to 45.
like its related but not same question
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i guess by inspection is the only way, but its so easy to miss one
also, I think you can have different answers but still be a basis
for example,
I had the same thing with E22
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Hi, I have a set of 2D data points that I'd like to calculate the PDF for. I've tried applying the PDF for all the X data points, then for all the Y data points and tried summing the PDF of X & Y. I was wondering if this is the right approach? Any guidance would be highly appreciated
Please don't occupy multiple help channels.
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stop opening so many
Hi sorry for the trouble, Im new to discord. I see that my query is being closed, could you please let me know why?
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does this seem right?
have you tried using a derivative calculator?
not yet
So do it. You will get fully worked solution step-by step. If you still have a question I will take a look
got it
supamen
okay firstly
don't do that
this is a differential equation, it's something else
secondly, you can't just move the xy out from d/dx; since y is a function of x (i'm assuming that, otherwise this is just basic linear equations) you can't do that. use the product rule for (xy)'
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hi, i thought i had the right idea for part (a) but i guess not. does anyone know why my method was wrong?
non-pdf version
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<@&286206848099549185> ?
I also got the same 💀
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hello
find the volume of the solid of revolution obtained by rotating the region bounded by y=√x and y =1 about line y = 1
can anyone help with this
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Hi!, im studying basic limits and I came accross this question. Ive asked websites, and the hints should be Limit chain rule and exponent rule. Can someone explain it?
aight
for this question you wanna rewrite $(1+65/x)^{3x}$ in terms of e
nosqldb
yes it is.
in general, we can do this for $a^b$ with $e^{bln(a)}$
nosqldb
so it should be $e^{3xln(1+65/x)}$,? Then how do I apply the chain rule?
GiddyBassoon535
well make it into a fraction first
you want $\frac{ln(1 + \frac{65}{x})}{\frac{1}{3x}}$
nosqldb
ok that's a new thing. What's next?
try to evaluate
just change the x with infinite?
Ok @frosty parcel I’ll try my best
Uhh ok lets start over
Like nos here said, we are able to rewrite our exponent as an exponent of e
This right here
Also I apologize for the bright light, its the best Ive got
See how in the limit we have e, which is a constant
So we can move that outside the limit indicator
I should remind you that the reason we placed e in here in the first place is because we need to find k, which e is raised to the power of.
Great.
So now in this limit, we can see 3 being multiplied by the other factors.
And 3 is a constant, so again we’ll move it outside the limit indicator.
Now say we use direct substitution
Inserting inf into the limit. Let’s see what we get.
We get inf * 0. Indeterminate form for an exponent.
Meaning that we can use L’H for exponents.
So now we have to rewrite our exponent in such a way that L’H will solve it.
So we put it as a fraction.
Again, nos was ahead of me.
We turn the x in the exponent into a 1/x
As done here.
.
However, they did not pull out the 3 (constant), which may make things a bit tricky as we go on. So I’ve done that for you.
Now, we can use L’H.
Wow good job Saturn
I assume you already know what L’H is. So I’ll just take the derivative of the numerator and denominator and put them back in the fraction.
,rotate
(Chain rule just so you dont get too confused)
Denominator
Now our fraction looks like:
Now make it a bit easier on the eyes, and add the limit.
Simplifying, we get:
Notice the 65 in the numerator. That is a constant, so we can place that outside the limit.
Oh hold on
I made a mistake
Here the x in the numerator shouldn’t be squared. It should just be x.
Here too.
Sorry
Now lets divide the entire fraction by x.
This shouldnt change the value of the fraction, since we’re dividing it by 1 (written as x/x)
Doing this we get:
And with direct substitution, we have:
Now, replacing all this back into our original equation.
Here.
We now know that everything after 3 in the exponent has a value of 65*1 = 65, as we have just calculated above.
So, we have: e^3*65
Which is…
Hope this solves it @frosty parcel
Also please tell me the game you found this in.
🧐
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i could not solve this problem, i have the solution but i did not really understand the idea behind it for example in the solution i see a pattern in the * and | so for example (2,3,6,9) = ∗ ∗ | ∗ | ∗ ∗ ∗ | ∗ ∗ ∗ |∗ and i see 2 stars than a bar then 1 star event tho it is 3 in the list so here i noticed that it is adding up 2+1 = 3 and 2+1+3 = 6 finally 2+1+3+3 = 9 and then the thing that i also dont understand is why there is another bar and star ?
solution:

for example what i thought about is +++ | ++ | +++ | ++ and this is wrong as the condition is not respected so why use 4 bars | ??
There's another star, but not another bar
4 bars ?
You need 10 stars, as the bars' positions within those stars are what you care about
Why is this wrong?
Oh it's wrong because there's 3 bars
its (3,2,3,2) and we must have w<=x<=y<=z
It's not. It's (3,5,8,_)
Every bar prints out a number. That number is the star count to the left of the bar
Oh ! i see but wait i just noticed this ? how did i solve the multi-set problems without this knowledge !
or is there another way to count the stars or am just out of my mind ??
I thank you Mr.@brave bramble for your help, that widened my knowledge and flattened the land that is yet to be explored. Good-bye!
I mean different problems might count things differently
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✅
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Hi, I'm getting true for this, but my answer key is saying false - any ideas? Current thought process is if f(n) is in O(g(n)), it must be at least as large as g(n), which should hold true as 2^f(n) and O(2^g(n))
Wym
Consider said 3lg(x) and lg(x)
oh
Yeah…
yeah
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im not sure how to do this. my thinking is that i can flip the sign on the last three elements in the given vector to create 3 new ones for each sign flipped. then use the gram-schmidt process to orthonormalize them
That should work, provided that the vectors have no zero elements in the last three places.
Why can't we just apply Gram-Schmidt directly to the given vector?
Oh we do need four vectors.
Why not just use 3 of the standard basis vectors?
If the given vector happens to equal one of the 4, use the other three
Then apply gram-schmidt
i feel this is easiest and probably what they were looking for but idk
i was told that the 3 other vectors im supposed to make shouldnt be parallel to the given one or eachother
Right. You need a linearly independent set of vectors to start. Problem is, flipping the coordinates of your vector is not going to guarantee this
yeah ive been spending a lot of time thinking abt that. not sure how im supposed to make 3 new ones which are linearly independant. apparently theres a pattern.
Again, why not just choose the first 3 of the 4 vectors standard orthonormal vectors that aren't parallel with the given?
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not sure how to do this in python. is there an easy way to check if two vectors are parallel? i assume you mean vectors like [1,0,0,0] right?
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@sly matrix two vectors are parallel if their dot product is the product of their lengths.
that makes sense ty. I should be able to solve the problem now. Would the given vector and the 3 other standard vectors be linearly independent just out of curiosity?
Ah, good point, it is possible that there would be no component in the other direction, like the vector is [0, 1, 1, 1] and you use the last three
In that case the simpler method would be, choose the first non-zero component of v, then choose the basis vectors that are zero in that component.
@sly matrix ^
Those will definitely be linearly independent and span the space
The first vector is complex. Should fix this problem no?
Remember that because this is a vector backed by complex numbers, your scalars are also complex. If your bases are e1, e2, e3, and e4 then vectors will be ae1 + be2 + ce3 + de4 with a, b, c, d complex
Like if your vector v = [1+i, 3+2i, 0, -4i] and you pick e1: [1, 0, 0, 0], e2: [0, 1, 0, 0], and e4: [0, 0, 0, 1] as the other 3 basis vectors, we can see v = (1+i) e1 + (3+2i) e2 - 4i e4
So they're not linearly independent
But if we chose e3 instead of e1. Then we'd never be able to make the (1+i) part of v with e2, e3, and e4.
@sly matrix ^
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You've misunderstood the question
They have already given you the solution of the DE to you
So you just need to substitute x = 0 and y = -1/4 to find c1
But yes c1 = -5 is correct
So just substitute c1 back in and you have your particular solution
I plug in c1 into y?
Yes, $y = \frac{1}{1 + c_1 e^{-x}}$
south
Yep
That’s it?
Yes
So I didn’t need to find y prime
No, you didn't at all
No worries man
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tried using power of a point only to get a quadratic equation
Before I start to look too hard into this one, be aware that sometimes you will get two possible answers that satisfy the mathematics, but the physical geometry will rule out one of the answers
If you solve for the quadratic you got, what two answers do you get?
What quadratic equation did you get?
Cool, probably just a sign mistake or something then
Ah did you do AB * AC? Hopefully you did