#help-33
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need help on 2 and 3
no
this is intro to linear algebra
your cooked
@gilded ocean Has your question been resolved?
<@&286206848099549185>
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I didn't understand the bit after a²>0
dekho
jo since ke baad 2nd step h
usme wo eqn ya to ek baar touch kregi axis ko
ya kbhi nhi kregi

@gilded cedar this is an English speaking server
i see many ppl suggesting in hebrew french
i just used hindi so its easier for him to understand
The users here are overwhelmingly english-only. If someone else shares a language with you, sure. But it's not recommended to assume so
its an indian book
@cerulean chasm are you fine with this?
A²<0 kaise aaya
0 hai
Han wohi kaisa ayaa
wo bs parabola ka mouth btane ke liye
kisi bhi real quantity ka square 0 se to bda hoga hi
Uske baad wale step mein quadratic ka D lesser than zero kyu hua
kisi quadratic eqn ko
agr >=0 hona h
ek sec diagram dikhata
Toh d=0 ya d>0 kyu nhi kra
greater than me 2 roots aate
Are bhai
Toh kya hua
isme niche wala part eqn ka neg nhi ho jayega
Zero nhi ho skta?
isme neg ho ja rha
Toh hamne sirf lesser than 0 wala hi kyu kiya
=0 wala kyu nhi
Arey hn liya h
Sorry
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✅
@gilded cedar agar x real h toh roots exist krne chahiye na
Jo y ke terms mein eqn thi woh?
Hn
Okay
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this is the solution to the question
i don't understand how they found Q(x). i understand that p(x) = (x-3)^3 times Q(x)
but idk how to find Q(x)
@narrow depot Has your question been resolved?
no
One moment.
oh wsorry lol
You should have learned about this when learning about Polynomial Long Division.
i learnt about the remainder theorem, the factor theorem and there was some rule about monic polynomials
that allows you to do things (but i don't remember exactly what)
and i think the answer did something about a monic polynomial siince it said "coefficient of x^4 is 1"
Anyways, because (x-3)^2 is a root, then (x-3)^3 is also a root of P(x). Expand (x-3)^3 and you will have a third degree polynomial. Divide P(x) by that expanded polynomial and you should get a linear factor as a result with no remainder.
That will be your four linear factors of P(x).
that is what i tried but im very confused with what happened
i'll send you what i did
the remainder doesn't equal to 0
,rotate ccw
Why did you stop at -9x^3?
-27x should become addition which results in 54x.
yw
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why is y not positive? wouldn't -5pi/6 be in the 2nd quadrant?
it'd be in the 3rd
hmm
dont worry the just did
remember for negative angles your terminal arm rotates clockwise
you're rotating fewer than -pi radians
maybe i should've just found the coterminal angle, 7pi/6?
if that helps
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Hey just need a little quick help I've done most of the work but for the empty answer f^-1(-31)= I keep getting no solution, like I'm solving and not getting any kind of answer. I'm not sure what I'm doing wrong.
I started with x^4-4=-31
and then tried to solve for x , x^4=-31+4 = -27
but it cant be -27?
helllllloooooooo
you haven't fully solved for x
u are at f^-1(31) ?
you have x^3 = -27 (not x^4, idk why you keep writing that)
true
yes
a) doesn't look right
how
i subbed -3 in the function then subtracted 4
what function?
f(x) = x^4-4
omg
i wrote it in my notebook incorrectly
thats why i keep doing it wrong
thx
okay so its -31
indeed
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so far so good
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Could someone assist me with how to do c)?
For a) I got x = (4-2t, 1-3t, -4+4t, t) with t being the free variable
For b) I got x = (8-2t, -9-3t, 7+4t, t) with t being the free variable
For c) (a) Make a system of equations:
4 - 2t ≥ 0
1 - 3t ≥ 0
-4 + 4t ≥ 0
t ≥ 0
I'm getting that this system has no solutions...?
Similarly for (b)
8 - 2t ≥ 0
-9 - 3t ≥ 0
7 + 4t ≥ 0
t ≥ 0
I'm getting that this system also has no solutions?
Feels like I went wrong somewhere since both my answers for c) are no solutions exist... would appreciate if anyone could confirm and tell me where I went wrong..
@sacred rivet Has your question been resolved?
Any <@&286206848099549185> know this?
4 - 2t ≥ 0 -> 2 ≥ t
1 - 3t ≥ 0 -> 1 /3 ≥ t
-4 + 4t ≥ 0 -> t ≥ 1
t ≥ 0
we could basically deduce that there is if t is between 0 and 1/3
Simplifying that gives:
t ≤ 2
t ≤ 1/3
t ≥ 1
t ≥ 0
So, there are no solutions that give x ≥ 0.
oh i did a mistake you are right
if we draw a 4 number lines they wont all intersect
b) should also have none lol
Hmm
That seems sus tho
lol
Could it be that is simply the answer or I may have messed up part a) or b)?
it could be either that
a) is right
b) too
lol
ye
What kind of weird question is this lmfao
you ask me
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@sacred rivet Has your question been resolved?
@sacred rivet Has your question been resolved?
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@torpid plover Has your question been resolved?
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U familiar with the binomial theorem?
Yes
consider (7 - sqrt47)^5 = Q
then, consider quadratic with roots P and Q
i do not recommend use binomial theorem on this question
Okay
o good idea actually
Yea if prererable id like to avoid skul
I was planning on considering odd powers for the fractional part thingy
what next
Find a relation between {P} and Q
rewrite P(1 - {P})
And use that to do this
yes that is fine
alr now the qn is the box
Kinda stuck
I can't see what mqnic is trying to do either
Let him cook
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Veni, vidi, perii
seems to be likely a conceptual error - bases are generally not unique
I know
but that aside, all you need to do is find linearly independent vectors in $Im(T)$
Element118
so you can basically do a bunch of substitution to find vectors until you find enough linearly independent vectors
@novel juniper Has your question been resolved?
so I Just brute force it?
that's one way, though another way can be rewriting it as a map on $\mathbb{R}^4$ and doing gaussian elimination on that matrix
Element118
hmm, okay
Thanks
why can't the basis have 4 matrices?
I was thinking $\begin{bmatrix} 1&0 \ 0&0 \end{bmatrix}; \begin{bmatrix} 0&1 \ 0&0 \end{bmatrix}; \begin{bmatrix} 0&0 \ 1&0 \end{bmatrix};\begin{bmatrix} 0&0 \ 0&1 \end{bmatrix} $
Veni, vidi, perii
some of these vectors aren't in the image
unless you are going to take T of those vectors
then of course the result would span the image
but then you have to check for linear independence
That's a very good idea
thanks
yeah, they ain't LI
ykw, that works
Thanks !
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wait this might seem like a dumb question
but how am i supposed to show my work for a limit approaching 3 from right
do i just put in in a table
you can show that as it approaches 3 it comes to some value, so maybe f(3.01), f(3.0001) etc
what kind of maths class are you in?
You can try direct substitution, though I'm guessing it's not that easy.
yea but what if like its a big polynomial function
Then you just need to show that the place lets call, 3+delta is such and such value
$\lim_{x\to{3}^+}f(x)$
Makenna
Analysis the function on the right side of x=3
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The curves f : y = ax^2 −3 and g: y = −x
2 +b have the common point S(−2| −1).
(a) Determine the functional term of f and g!
(b) The two curves f and g define a finite surface area.
Sketch this surface area!
(c) The surface area rotates around the y-axis.
Calculate the volume of the resulting solid of revolution!
Its what i have made
But pro
But problem is C
I think i calculated it wrong
From the graph it seems like intervals are -3, 3
The area does go from -3 to 3 but you got the formula for the integral wrong
You aren't going to subtract the integrals
So i have to divide it and find the volume then add together?
Yeah divide it up in the 2 sections and add up
Thank you!
If you take the functions you derived for f(y) and g(y) you get this
Also how do i know the intervals without the graph
It's always helpful to draw out a graph to see but the intervals here go from the vertices of both parabolas to their intersection
And both of those can be calculated algebraically
I see
Here the intersection is f(x) = g(x) and the vertecies are f(0) and g(0)
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you messed up with the quadrant
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✅
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How do u understand these kinds of texts. Is there a math topic for it?
probably coordinate geometry
No I mean some things in a math book goes like "let x is something set of defined"
proofs?
Which is hard to understand (or maybe I just have bad reading comprehension)
You mean set theory?
Idk
this looks like set theory
Hey! I am working so hard, but still not getting the helpful role ☠️
I'll send another ss if I find another text of those
🤞
there isnt much to it except you will understand it when you learn about the topic
this is just calculus
Cuz usually I just resort to videos if it's like that
yeah this is 100% reading comprehension issue
But I think I'm missing something out if I don't understand the texts
Rip
i think it is just matter of building up knowledge
a lot of things wont make sense if u dont have the foundation for what is before it
cant really except to run before learning how to walk
Hm idk but that's possible
But I think it's more of a reading comprehension problem since I understand the concept when watching a video of it
i think it comes over time
like the first time you come across dense blocks of maths it can feel a bit like wtf is going on here
but if you just watch more maths videos, read more maths etc. you'll get a sense of normally what they're trying to do in the proof and you'll get used to it more
also some ppl are just slow readers - it's fine if it takes you multiple readings to familiarise urself with the topic
i think maybe if you haven't done like an introduction to uni mathematics course then it may be helpful to do one to become more familiar with stuff like this
working through this may help
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<@&268886789983436800> ads
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Yoo
factorise
w + iw = 1 + 7i can be factored
System of Equations
um.. how

what can i do with dis tho
now find w
1+7i/1+i?
nah gotta realise the denom
oh
yes, w = (1+7i)/(1+i), and now rationalize this
wait so i dont have to turn w into a+bi

.close
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i need help solving those
so first of all number a do i take the bracket down and turn it up and reverse the power
@flint edge Has your question been resolved?
which question are you talking about
oh a
for a: multiply and divide the function and then simplify and then substitute 3e^-x + 4
for b: substitute the entire expression under root
for c: its really easy just do it
for d: first of all use trigonometry formulae to simplify then integrate
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I need help with solving the area of the trapezoid, I tried to work it out and I got 16cm^2 but my program says its wrong, what am I doing wrong?
for shapes like these you can break it down into the elementary shapes
so the total area of this shape = area of parallelogram + area of triangle
alright, But im still confused on how to work out the areas of the shapes
for this parallelogram do you know the base?
isnt the formula for the parellergram bxh?
yep
and then for triangle its bxh/2?


is the measurements for the triangle 3x4?

ohhh
good insight
so would it be 20+12?
ahh love when that happens
so it would be 32?

it still says its wrong?
im not really sure anymore-
hello?
hellloooooo
you there
you got the triangle area wrong
yea
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sorry had to do something
but yeah I didn't catch that my fault
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Help
ask
define nicely
pre calculus is important
Straight up rock bottom
What is that
there are many prereqs to knowing calc
calculus exists due to the limitations of algebra especially when it comes to infinity
Hmm
So algebra
you should have a solid foundation in algebra
K
ability to derive formulas and also knowing how to manipulate questions to get the desired answer
etc.
I know poly butwhta is trug functions
Hmmmm
practive trigonometry
Questions of this
I want to practice
I want to know what type of it
that or there are resources online
Hmmm
I will try to find
Thx for the help
I will practice regularly
And improve
Love y'all thx pajama and alaska
beginner or
Begnner
do you have atleast some knowledge
alr
open stax
good intro
@balmy root try khan academy
for lectures
I only had S.L Loney's Trigonometry but not if you are a complete beginner
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f(x)= logx/x find the point of local maximum of f(x)?
the local maximum points have to be such that the evaluation of the first derivative will vanish
u mean substitute f'(x)=0
impose*
?????????
as I said you have to impose f'(x)=0
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I think it is a pretty easy ex but I am stuck on 2 b and it is the beginning of the year and I still didn't recover everything I learnt
So could anyone help me out on how to answer this question and the questions after
@upbeat helm Has your question been resolved?
<@&286206848099549185>
to study the relative position between (C) and (d), we study the sign of f(x) - (x-1)
I did that
in intervals where f(x) - (x-1) < 0 => f(x) < (x-1) => (C) below (d)
in intervals where f(x) - (x-1) > 0 => f(x) > (x-1) => (C) above (d)
where f(x) - (x-1) = 0 => f(x) = (x-1) => (C) intersects (d)
so according to the question
If I were to draw a table of sign the sign between -infinity and 1 (which is the condition) is minus?
And for the part a, you have to find the limit of f(x) when x - > +inf and when x - > -inf
And then you have to compare it with the line y=x-1
I don't get it
I mean, you have to prove that the line is asymptotic to the function. And asymptote means, that the value will approach the value of the line, but it won't exactly be the same.
yes, minus
Which part is this?
So, if you find the limit of the function f(x) when x approaches to infinity, you can compare it with y=x-1
2 a
I am done with that
Oh sorry
I wanted 2 b and the ones after
Np
I though you asked for the whole part 2..
no
I think
But I didn't realize why did I put minus
what is f(x) - (x-1) ?
2x-4/(x-1)squared
the bottom is (x-1)² > 0
Like we multiply the signs
yes, if it was (x-1)
uhh yes
so it is positive
yeah, and what is positive doesnt really play a role in sign determination
so the sign of f(x) - (x-1) is fully determined by the sign of the top
2x-4
top = numinator...
Just for clarification
show me the table!
so should be something like this where minus is F(x) under D and plus is above
srry for bad writing but it's my first day lol
but we said that (2x-4) is what determines the sign
Yeah
no :p
substitute by a value less than 1
One root
and by 1
and for x=1 ?
Math error
we're talking top onlyyyy
its -2
negative as well
it doesnt switch sign at x=1
find where it switches sign :p
yeah lol, idk how
CONGRATS
Thank you xD
I am grinding for that color since 3 days now 😭
i dont even know how
Grinding on my frozen brain
I have heard that there is a bot which sees the progress in these help channels...
But you got the Active role... 🫢 Which is different from the Helpful role
Yeah I saw
I dunno what's the difference lol
@upbeat helm so sorry for disturbance lol
Are you clear?
who knows, maybe it comes right after
but theres also Very Active
maybe that, then Helpful
what is ittt
Because ai tried both 1.5 and 0.5
you dont just try, theres a way
both giving negative values
Ik
if you want to know where (2x-4) changes sign, put it =0
It gives 2
2x-4=0
2x = 4
x=2
I noticed
yess
But I remember we should write a condition when we can
Doesn't x = 1 gives a 0 in dominater
Is not that the reason why we do that
,rccw
Right
to indicate that x=2 zeroes f(x) - (x-1)
and below x, write f(x) - (x-1)
and its good
Do you mind completing the ex with me?
I used to Master these but I just need to remember them
Can you?
youre welcome
have a nice day both!
Sup
No don't leave 😭😭
OMG tbh, I don't understand these notations anymore 😭
Yeah ask for help... someone else can help better
Alright
Np
You have no excuse imagine doing all this help for only a discord role

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I just love that color... 😔 🫶
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does this evaluate at infinity
sheesh what level is this
medium
could u help me with mine
nah
oki 🖕
btw this is my work on this
oh lim n -> infinity of sum from k =1 to n of 1/k is ininfinity
so that gives me infinity still
so i guess infinity??
<@&286206848099549185>
oki doki
either u can help me, or you watch, 1 out of 2
whats your homework about
it already got solved
k
ur problem looks hard
yea
u cant know that
what's popping
- not a lady
- dont ping individuals its mean
it's mean value theorem so true
?
also if you are not why do you have wrong pronouns
you are genuinely causing a confusion
sorry
no it's good
is my work rigt?
right?
like i got infinity as wolfram said but is the solution right
let me see
.
How'd you get the n^3 in the second step? Shouldn't the k^2 in denominator be divided by n^3 and added 1
this is the only mistake in my work
since the sum is not indexed by n, i can pull it out
its indexed by k
can i not pull it out
you can pull it out, but not the way you did
Yeah but shouldn't the denominator be (k^2)/(n^3) + 1
,, n^3+k^2 = n^3 \left ( 1+\frac{k^2}{n^3} \right )
bacc
that does not change anything does it
im pretty sure i pulled it out right
,, \lim_{n \to \infty} \frac{1}{n^3} \sum_{k=0}^n \frac{k(k+2)}{ \left ( 1+\frac{k^2}{n^3} \right )}
bacc
You have written only k^2 in denominator
This is right
..
and that turns into what
[ \lim_{n \to \infty} \sum_{k=0}^n \frac{k^2+2k}{n^3+k^2} ]
[ \lim_{n \to \infty} \sum_{k=0}^n \frac{n^3+k^2+2k-n^3}{n^3+k^2} ]
[ \lim_{n \to \infty} \sum_{k=0}^n 1 - \frac{n^3-2k}{n^3+k^2} ]
bacc
[ \lim_{n \to \infty} \sum_{k=0}^n 1 - \frac{n^3}{n^3+k^2} + \frac{2k}{n^3+k^2} ]
bacc
i know what you meant
but the issue is we can only do that if we know that the sum exists
really?
yea
i didnt know that
so you are saying i can do $\sum_{k=1}^n a+b = \sum_{k=1}^n a + \sum_{k=1}^n b$
OH NO
what d a do
sum_
daniel
yeah
yes
yes
otherwise if they dont you might get funny things because things get strange with infinity
hah
im thinking
how we could simplfy this further
what is the value of n inside the sum when k = 1 ?
is it infinity?
i mean not literally, it doesnt reach it
but yk what i mean
ah yea i dont think the approach will work
why
haha i dont know how to continue
señor matlåda
whats the original question
Maybe we can approximate it if we neglect k^2 in denominator?
Yeah it does converge
we could neglect it
I think
,, \lim_{x\to \infty} \int_1^x \frac{t^2}{x^3+t^2} : \dd t
bacc
for soem reason this integral yields the same value as the sum
even though it's an approximation and we also integrate
[ \lim_{x\to \infty} \int_1^x \frac{x^3 + t^2 -x^3}{x^3+t^2} : \dd t ]
[ \lim_{x\to \infty} \int_1^x 1-\frac{1}{1+\left ( \frac{t}{x^{\frac{3}{2}}} \right )^2} : \dd t ]
bacc
That would be arctan basically
[ \lim_{x\to \infty} \left ( t - \arctan( \frac{t}{x^{\frac{3}{2}}} ) \cdot x^{\frac{3}{2}} \big |_1^x \right ) ]
[ \lim_{x\to \infty} \left ( x - \arctan( \frac{x}{x^{\frac{3}{2}}} ) \cdot x^{\frac{3}{2}} - 1 + \arctan( \frac{1}{x^{\frac{3}{2}}} ) \cdot x^{\frac{3}{2}} \right ) ]
Maybe we neglect the 2k in the numerator also
(My physics friend would be proud of me rn)
That'll give us ( k^2)/(n^3)
bacc
That can be transformed into integral
bacc
so t^2/x^3
Yeah
i just fear it's too big of an approximation but sure
idk how to evaluate this but it's 1/3
Yeah
so basically lim x->oo t^3/(3x^3) from 1 to x so
x^3/(3x^3) - 1/3x^3
it works
lol
you also get 1/3
weird
I understood leaving out 2k but also k² from the denominator
but honestly
we only considered the dominant terms in the numerator and denominator
so that might be it
[ \lim_{n \to \infty} \sum_{k=1}^n \frac{k^2+2k}{n^3+k^2} ]
[ \leq \lim_{n \to \infty} \sum_{k=1}^n \frac{k^2+2k}{n^3} ]
[ \leq \lim_{n \to \infty} \sum_{k=1}^n \frac{2k^2}{n^3} ]
[ \approx \lim_{n \to \infty} \int_1^n \frac{2k^2}{n^3} : \dd k ]
bacc
Anyway is 1/3 the answer?
wait
it could be either way 2/3 or 1/3
the problem with the 1/3 is we need to approximate correctly
if we leave terms out that then that either makes the sum greater or less
leaving out k^2 makes it greater but leaving out 2k makes it less again+
but I can surely write instead of k^2+2k <= k^2+k^2 = 2k^2
is the answer 1/3?
señor matlåda
yes
Yeah but my method is by neglecting a lot of terms so idk if it's even right
It is?
,w Limit[Sum[(k^2+2k)/(n^3+k^2),{k,1,n}],n->inf]
yea i am a bit confused but whatever
at least it converges
not infinity haha
same i ended up with just x2dx
my guess is the idea is to leave out non dominant terms
We should be happy it does
kick everything other than equal power
Maybe, but we can't say it's exactly equal to the initial limit
no its not
limits are not exact anyways
Indian? Yeah
wdym by that
yeah
so i only consider 1/n³?
ill just write it
you dont know my limit
You shouldn't do it in maths, but in other fields they just neglect the terms that make it a hard problem
yea
integration as a limit of sum
bacc
now what
That notebook screams Indian to me
😂
its record book
Notebook
For me it was the handwriting
now do you know what integration as a limit of sum is?
if yess apply it
no explain it
please
you must be very smart at school
i wish i had the time ,the best i can do is brief
youre right
Buddy you're a math guy, trust me you don't wanna know what else we do in physics
oh nvm i see it lmao
you dont need an explaination?
if you got no time, then no
Is that sarcasm I see?
ill give you a smol explaination
yes please
cause i didnt get it
seems like wizard lizard math
What is b1?
yes whats b1

