#help-39
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But the instant at which you calculate the rate of decrease is when the voltage has dropped to 8V
huh
This thing that you did
You evaluated V(t) = 8
But in their solution they dont need to calculate that
You solved it to find the time
but since their method directly uses the voltage, they dont need to do any other calculations. They can just plug in that 8
but to find the rate of change they need the derivative and the derivative has 14
wdym?
No
Like this
OHHHHHHHHHH
OK thanks
damn
wait i have one more question
i cannot for the life of me get this
what al i doing wrong
What is dP/dr when the perimeter is minimum
wait no part A
isnt that for the circumference

BD is the diameter of semicircle
ok thats not fair because
theu shouldve stated r was the radius
you know what i mean
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did I do something wrong when I integrated it? The textbook answer says it is pi/4
not in the integration
this is what the worked sol do
whys it that when i dont use u sub i get a diff answer
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what the hell đ
u = sin^2(x)
1/(1+u^2)
the
okay so what happened here is that they subbed u= sin^2(x) but wrote u^2 in the denom instead of just u
which happens but shouldnt in a book lolol
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Hello, I need help with one maths problem regarding trigonometry in cuboids
do you have the quesstion?
Hang on
I'm just not sure how to calculate the angle if it is not already in a right angled triangle. The only thing I did was calculate the length of CG
But I just can't see how that would help me - without the right angle
!showwork
Show your work, and if possible, explain where you are stuck.
especially your calculations for CG
,rccw
That's what I've got so far
the question statement has a typo
you're using the same symbol "H" for two different things. that's not a good practice in math
that should be avoided in any topic and any level of math
cuz you don't wanna confuse your markers, who have to grade hundreds of questions
if you're not patient enough to read into your solution, you'll risk losing marks
just write the name of the segments in the ratio of segment lengths
Okay I'll fix that
a general problem solving mindset:
if you're blocked, think about what given condition(s) that you haven't used
You mean like the info in the instructions I haven't used yet?
So, we've got GD - 6cm
in a question statement, each given condition has a "reason" to exist, in general
Yeah, I figured
But I just don't see how that can help - in order to calculate the angle we need a right angled triangle somewhere, right?
he mean like find Everthing u can find
With the questionâs given information
CH and HD would be useful
the above two mentioned segments nice exercises, and provide an optional pathway to the desired solution
Sorry, what are segments? English is not my first language when it comes to math terminology
But I just don't see how that can help - in order to calculate the angle we need a right angled triangle somewhere, right?
to solve a puzzle, you often have to work from both ends, in two opposite directions
- "forward" direction: from the "start", use the given conditions
- "backward" direction: from the "end", also use the given conditions
- to derive equivalent statements
- to derive some necessary conditions for the desired result to hold, so that we can eliminate the cases that don't satisfy those necessary conditions
What do u think
you can start thinking from the "backward" direction:
the question asks for "angle XYZ"
so that does "angle XYZ" means?
||angle between segments XY and YZ. then you can look into these segments, and ask yourself again, which given condition(s) you haven't used, so that you're blocked?||
Well either way we calculate, we're missing info. If we do a traingle of the base HD we only know 90 degrees. We still need more. And if we did it as AH being the base - same thing, unless the sides are squares, in which case we may get 45°. (Maybe?)
Sorry if I look stupid I'm not a math genious
Well, the 6cm are still quite unused. I think
I'm sure this problem is really simple and I'm just overthinking it
Well 6cm is only useful in two ways, as GD and AH
But GD isn't in anyway connected to CH ?
no they're disjoint
What does that mean?
Okay, so GD and CH are disjoint
one more condition that you haven't exploited enough
try really diving into my "backward reasoning"
by analysing the literal meaning of the required answer
We've only been given 3 conditions : 21cm, 6cm, and 12°. We've not used 6cm a lot. Could 21 be helpful again?
- try to write in complete sentences (i.e. sentences with complete mathematical meaning) that would make your messages easier to be read (by others and by yourself when you're revising it later)
- again, look into what's being asked, and try to interpret that, and find some relevant idea(s)
Okay
@hallow falcon Has your question been resolved?
Okay so I'll leave it unsolved for now and ask about it to my teacher at school - in my native language which might help a bit. But I want to thank you for your time
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for d, i get why the bounds can be 1 to 0 but why cant the bounds be 1 to -1
(Sorry just curious how to get -1)
yea like when i imagine it rotating along the y axis i imagine both bounds having the same volume
ok well heres the thing
when you rotate around the y-axis
both the left half and the right half sweep out the same region in space
but the trouble is, you're gonna end up sweeping it out twice over
so you get double its volume at the end
that is why you only take one piece!
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hi
oh
okay
because i think i did it wrong in the exam
anyways
so
could u theoretically do
Which?
B-A = C-D
AB = CD, AD = BC
yes but for vectors
like here
to get to point D
lets say point D is unknown
Couldnt you solve for D then
OH
Yes yes itâs true
If you have the rest of the points you can find D if thatâs what youâre asking
Do you have it to show or you donât need?
yeah
ok wait
@rough forge dude
đ đ
ich hav vergessen
so here
i did AB = DC
seems right
hello
If you do a -b = c - d I think it works
wasnt it like this
Now solve for C
yeah ok
but wait
woher weiĂ ich ob
Like how do i know where A B and C is generally
or D
Hold on man idk German
make a rough sketch and from there a good guess
Zu drei gegebenen Punkten, die nicht auf einer Geraden liegen, lässt sich ein vierter Punkt finden, sodass alle zusammen die Ecken eines Parallelogramms bilden. Dabei gibt es drei verschiedene MÜglichkeiten. Welche das sind und wie es funktioniert, erfährst du in diesem Video!
âââââââââââââââââââââââââââââââââ
Wenn du dich auf eine Mathe PrĂźfu...
I mean if you need to have it in order ABCD which makes the most sense itâll be b - a = c - d
wohl gemerkt, there are many way to construct a parallelogramm
i think das video will helfen
Youâll get for C (13,10,12) which makes sense because a and d itâs +1,+2 and +8 difference and so will be c and b
Alr
hm ok
i got an exam firday
so i gotta imagine it in my head
đĽ day
Imagine what?
@daring bay Has your question been resolved?
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Is this right?
I wouldn't say so no
Ok! Which parts are incorrect?
the second step looks off
Maybe you should solve the integral on pen and paper and see what order you do stuff in
instead of guessing
that looks better
Thank you!
@copper yoke Has your question been resolved?
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hey
is the ans 0?
So its infinity minus infinity which is indeterminate
So you would need to solve it how you would approach an infinity minus infinity problem for limits
how can i do that
Organic Chemistry tutor indeterminate forms guide
I mean lets do some thinking though if you dont wanna watch that
What you can do is multiply by the conjugate
And then take the limit of that
What is the conjugate of (n^2 + 2n)^1/2 - nâs conjugate?
wouldnt that become complicated cuz theres a -n
can i divide by n instead?
Nah dont do that
Do the conjugate
But you can try divide by n and multiply by n
And try lâhopitals
But the conjugate will make it easier
Imo
ok
Sometimes the problem needs to get harder to be solveable
do you know what a conjugate is?
I was about to ask that too
lmao ofc its like the opp sign
show us
Ig so send us the conjugate
@dawn trout Has your question been resolved?
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broski it's almost 11pm
i ain't studying at this point
but sure let's take a look
pretty sure this part is wrong
oh
fair enough

i have doctors tomorrow
i'll come after lunch i think
yeah i just come for friends and studying
How do you know I-A^t = A - I on line 2
Oh youâre just changing the left side and rewriting the right side from the top
Whatâs happening on the third line
@naive marlin Has your question been resolved?
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can someone explain why the order of this differential equation is 1 instead of 2?
does there need to be parenthesis around the ^(2) in order for it to be order of 2?
$(dy/dt)^(2)$
ScriptedEli
The order depends on the derivative order
it's the order of teh derivative
Not a power of the derivative
for f(x) would be 1st order
the degree and order are differentâthe degree being the highest "power"
f(x) is 0th order
this is a confusion over notation maybe
d^2y/dx^2 would be second order
but why is it not 2nd order? since it's squared?
This is first derivative squared
It is of order 1
$\qty( \dv{y}{x} )^2 \neq \dv[2]{y}{x}$ but $\dv[2]{y}{x} = \dv x \dv{y}{x}$
jan Niku
yeah i think so
like this is 5th order right?
because (5)?
but the (dy/dx)^2 is not 2nd order?
A common notation at least
no
it would have to be (2)?
(2) isnt used
This is first derivative squared
normally
(y')²
you start using () after the third order
yeah gotcha
but for leibniz notation, i dont think u use it at all
oh okay
you would just do $d^3y/dx^3$
ScriptedEli
?
yes
mhm
okay this helps a lot, thank you!
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hi
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Hey I was wondering how to set the bounds of intergration for these integrals In the answers they just do it and ther elogic doesnt make sense I get if theres a photo therir sometimes but if a differnt case is there a method to use to identify what to do
what other cases are you thinking of? here it's 0 to pi because you only need half a slice to spin around in 3d, and 2 to 0 because that's the value for the u-substition at the previous integral bounds
right but if I didnt have the drawnig how would I know that
for a lot of polar problems you either need to find where the function hits 0 or draw a picture to know what a slice is
or could I deduce it
right
okay
do u mind if I try find another example real quick
ill be fast!
yea that's fine
oh full 3d triple integrals will look different from the slice method yea
you don't need to try and draw a slice you just want the bounds of the radius, z, and angles
actually sorry I think I phrased my quesitonwrong my understanding isnt the best
I think this is a better question
what is splitting and like why do we do hence when does it need to be done
some shapes require two functions to describe
like here the radius has one function for most of it, but get cuts off at the top short
for a) it's because as you go from small to big r, the z is either between the flat top and bottom curve, or two curves, and those are different formulas
@rare jay Has your question been resolved?
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,w lim x to infinity (5x^1/2 + 1)/(x^1/2 -7x)
divide numerator and denominator with highest degree term
(denominator overpowers numerator)
which is x right
it's easy
yes indeed
so u get 0 + 0 / -7 + 0?
I was looking at the 1/2 thinking that was the highest term đ
okay thanks everyone
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f(x) = (sqrt(x^2 + 4x)) / (-x-4)
use lim x to infinity f(x) and lim x to -infinity f(x) to find horizontal asymptotes
I'm so annoyed at myself for not being able to do the algebra properly!
I see square roots and I fold instantly
$f(x) = \frac{\sqrt{x^2+4x}}{-x-4}$
Krish
just making it easier to read
im not the best at asymptotes but uhm yeah good luck im sure someone else knows
I know the asymptote part I just don't know how to get rid of the damn square root
I've done like 10 problems like this today and I still can't do it myself đ
uhhh L'Hopital's? because wouldnt it be inf/inf when evaluating at x=inf
it is not needed here
perhaps a simpler way is to divide both the numerator and denominator by the leading term
wdym?
my thinking was get rid of the square root
and then u assess the degrees
Have you tried squaring it
nah, I'll try rn ig
try dividing numerator and denominator by x too if you want an alternative method
a conjugate base is part of the bronsted lowry acids and base theory
acids and bases come in pairs
okay so just dealing with the top part
sqrt(x^2 + 4x) / x how would I do that?
would I factor out x or smth inside the sqrt
and for squaring it, how would that affect things? (sqrt(x^2+4x)^2
my algebra is cooked
numerator becomes x^2+4x denominator because (-x-4)^2
okay so it gets rid of sqrt
yeah
why are dividing by x and squaring both viable options?
seems like squaring is the easiest way to get rid of the sqrt
We can square it because $\lim (f(x)^2) = (\lim f(x))^2$ assuming the limit is convergent
purururuuriuruin
okay idk what that means but I'll look into it
so I squared and ended up getting x(x+4) / (-x-4)^2 which I turned into
In english its "the limit of the squared is equal to the square of the limit"
yeah
x(x+4) / (-*(x+4))(-x-4) is what I ended up getting
so that the x+4 can cancel out and we're left with x/(-(-x-4))
seem about rihgt?
yeah
so then it's easy to figure out the asymptote stuff after that
it's just so annoying knowing the work needed to solve but not being able to bc my algebra sucks
I'm really hoping enough practice fixes things
thanks for the help
there is another step you need to be careful of. Since we squared, we actually found the limit squared. So if the original limit is 3 that means we will find this squared version to have a limit of 9.
Similarly if the squared version has a limit of 9, then the original limit may be -3 or 3 (because (-3)^2=3^2=9). You can check which one is the correct limit by checking whether the expression you are taking the limit of is positive/negative for large values of x.
O_O
Yeah there are a lot of algebra tricks you need to know for limits its a bit annoying
so whenever I perform square or smth I need to apply that to the a in x-->a?
yeah
it didn't seem to matter since it was infinity though, I found HA fine. it just applies to when it approaches smth specific?
infinity^2 still infinity ig that's why
Hmm I think I might have misunderstood
wait but -infinity
You don't do anything to the x -> a I see what you mean now
,w lim x to infinity (sqrt(x^2+4x))/(-x-4)
,w lim x to -infinity (sqrt(x^2+4x))/(-x-4)
yeah I think I did something wrong
Assume we had $\lim \frac{\sqrt{x^2+4x}}{-x-4} = -4$ (this is not correct but just for the sake of demonstrating what we are doing).
What we are doing is squaring both sides
$\lim \frac{\sqrt{x^2+4x}}{-x-4} = -4$
$\implies (\lim \frac{\sqrt{x^2+4x}}{-x-4})^2 = (-4)^2$
$\implies \lim (\frac{\sqrt{x^2+4x}}{-x-4})^2 = 16$
So we found $(\lim \frac{\sqrt{x^2+4x}}{-x-4})^2 = 16$
So we take the square root of both sides to get
$\lim \frac{\sqrt{x^2+4x}}{-x-4} = \pm(-4)$
So the answer could be -4 or 4, you then just check large values of x (for limit x -> infinity) or small values of x (for limit x -> -infinity) to see which one is correct
purururuuriuruin
I get it, yeah
From this you can see the limit of the square is 1, so to find the original limit you find the "square roots" of 1: which can be -1 or 1
yeah, that makes much more sense
To identify which one it is you think about what happens when you plug in large values.
For $f(x) = \frac{\sqrt{x^2+4x}}{-x-4}$
numerator is always positive here since its a square root and square roots are never negative
denominator here is negative for large values of x (ex: -1000-4 = -1004)
and is positive for small values of x (ex: -(-1000)-4 = 1000-4 = 996)
positive / negative = negative, so for the x -> positive infinity you know the limit needs to be positive
positive / positive = positive, so for x -> negative infinity you know the limit needs to be negative
purururuuriuruin
positive/negative = negative so x--> pos inifnity needs to be pos?
I don't get why this is negative
,w lim x to infinity (sqrt(x^2+4x))/(-x-4)
positive numerator makes sense, denominator negative makes sense. so should be negative (I mean I think so at least since the answer is negative), I just don't get why bc we did the algebra and it ended up being x/x+4 which is positive/positive
Its because we squared the limit, so the limit is going to change.
So we have $(\lim)^2 = 1$. This is a quadratic though and we know to solve this we would get $\lim = \pm 1$
purururuuriuruin
Yeah
and we go back to the original limit to figure that out
Maybe you remember when solving square root equations you get "extraneous solutions". Its kinda like that
yeah I don't remmeber that lol
what do we plug in?
large values of x (for limit x -> infinity)?
Yeah.
sqrt(x=5) numerator is positive and bottom ends up being -5-4 which is negative
so u get positive/negative meaning the choice has to be the negative option between +- 1?
ye
thats wild
I get it though
just a bunch of algebra that I needa hope I remmeber for the examl ol
thanks for the help, really means a lot
np
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$\sqrt{-1} \times \sqrt{-1}$
SELVATOR
We cant say $\sqrt{-1 \times -1}$ right?
SELVATOR
you cant use that exponent law when on complex numbers
we can't say they are equal
oh yeah
SELVATOR
yes
@orchid heath Has your question been resolved?
we can call this complex number. we introduce complex number to expand real number place.
as u know, this is very strange. how can we redefine about sqrt(-1)?? for completion of the numer space......
âaâb=â(ab) only and only if a,bâĽ0
What if a = 0 or b = 0
â¤ď¸
Now it's alright
You can use iota if this condition is not satisfied
Like â-9Ăâ-4=3iĂ2i=6i²=-6
But don't try to combine the roots
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How do you find your answer after long division?
Idk where tf I find my answer
It says it =x+12
Is that just based off what's on the top,m
?
Yes, it's what's at top, plus the remainder over the original divisor.
So, (x + 12 + \frac{0}{x^2 + 10x - 24}).
Chai T. Rex
Chai T. Rex
That's because if the remainder is 0, you can ignore it.
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Hello.
can someone please explain to me how to do this
I haven't done this problem yet and I'm a little confused on where to start.
okay so
what I have come up with is sqrt2 / 2
for A
evaluated sin took care of the sin -1
got sin -1 ( - 1/2) = pi/6 substituted it back to get sin (pi/12 + pi/6)
used sum identify for sine and plugged in and substituted and simplified until eventually I got the 3 sqrt/2 + sqrt2/8 and then 4 sqrt2 / 8 = sqrt 2 / 2 and that's for A...
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What does it mean for f:R to R again in this context?
I haven't taken an analysis course in a year now
Is it just saying from x to go to y?
Oh, the question is "Determine if the functions are injective/surjective
@cedar scarab Has your question been resolved?
f:R to R implies that the provided function is defined for real number inputs only, and the output of that function is a real number too
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Is this correcr
Yes this is 'correcr'
Welcomee
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i need help with this question
``$\ell$im'' is quite the sight...
Ann
It's a fancy limit
random things but they werent much useful
im ok
yes
if you try to squint a bit and reason somewhat informally, the general term of the sum looks like k/n^2
question is, how far off does that put us
ie what does $\sum_{k=1}^n \paren{\frac{k}{n^2+k}-\frac{k}{n^2}}$ look like, and can we maybe put some upper bounds on that?
Ann
the limit of n->inf of this function ?
yes
mm yeah kinda
i think it will be too small in comparison to sum k/n^2
so we can ignore it if x-> inf
n not x
wrt k/n^2
yeah mb
ok so
yes
so you need to place some upper and lower bounds on the "remainder" sum
a lower bound is free: 0
what is the exact reason for this ?
i just felt like it
mmm its not that it will be small in comparison to the main sum
more that it will be small outright and hopefully maybe approach 0
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help
My question is (sorry the task is german) if the solution is correct because Im pretty sure x3 = 2-x4
and not -x4
I might be wrong but dont I have to solve x3 + x4 = 2
so I put -x4 giving me
x3 = 2-x4 no?
,w rref[[1,0,-2,0,-3],[0,1,2,-3,7],[1,0,1,6,9]]
from the last row u should get x3+2x4=4 so x3=4-2x4
so basically the solution is entirely wrong?
it depends if u made an error in row reduction
No thats the solution from last semester exam and im trying to figure out how they got x3 = -x4
so I was assuming their reduction was correct
therefore not understandy how they got it to x3 = -x4 since if I use the same reduction they got I get x3 = 2-x4
i used a calculator to get this
they got x3=-x4?
yeah wrong solution or wrong problem
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np đ
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Can someone explain how this equation works? To me it seems to be overestimating the area, because the blue equation would include the area bounded by the cos2angle equation and the x axis, which would also include the area represented by the red equation
The lecturer here states that the blue equation specifically represents the "crescent shaped area" but I don't understand
yep
think of standing at the origin and shining a flashlight as your rotate counterclockwise
Ok i think I see
the wall for the first pi/6 radians is from the circle
and then after that point the wall becomes the figure 8
Yeah i see it's the area bounded by the alpha and beta angles
Not the area under the graph
yep
most people try to do polar integration as they would normally
it is not the same
because our independent variable is theta, not x
changes in theta correspond to rotating a ray/line rather than sliding along the x axis
Its still a little hard to understand but I get why I'm wrong at least.
Thanks btw I'm gonna keep working at it
look up ap calc bc polar review videos on youtube
its like
a 50 minute video
towards the 40 min point he gives a nice intuitive explanation
lemme see if i can find it for you
đ
In this AP Daily: Live Review session, we will discuss the most common types of problems involving polar equations that have appeared on recent AP Calculus BC Exams within both the free-response and multiple-choice sections. Special emphasis will be placed on solving both free-response and multiple-choice problems involving motion along a polar ...
here you go
@lament pond
Okay thanks, I'll look through it
And I'll try to reread what you said once I understand more
I don't want to ask u a billion questions
no worries
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i dont understand what even is a semi parabola
what do i do
well, they probably touch at a few points
so find points x where (call the first function g and the second f) f(x)=g(x)
(so literally compute f(x)=g(x))
that's the first step
so x-1 = 3sqrt(x-1)
indeed
then what
ohh
because then that means the functions share a common point (i.e. "touch" since they are cts functions) at each (x,f(x)) or equivalently, each (x,g(x))
ok i gotta go study for something now :^) if u need help with the integrating part, probably someone else will stop by here.
alr thx
it's not too bad as long as you remember that the area you'll get is positive when $h(x)\geq 0$, negative otherwise
00100000
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you can divide top and bottom by h and then recognize this is a ratio of derivatives of log(cos(x * constant)) at x=0 for two different constants
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how the hell did anyone think of this
lol
is there some reasonable way of thinking about this which doesn't look like it was fathomed by a crazy person
or just like some motivation as to why anyone would think like this
Probably thinking of matrices as rotations in space
i'm not too comfortable thinking about matrices within matrices in the first place
like I understand it but I don't have much intuition about it
I highly recommend this guys video on matrices:
https://www.youtube.com/@visualkernel
the first one?
Just all of them about matrices, really helped me think of them as rotations in space. And of course 3blue1brown also has a fantastic video series on them.
oh I've seen that one
EoLA
I do know how to think about matrices as transformations
just the matrices within matrices thing throws me off
I haven't had those, but I think they're called tensors
Maybe look up some videos about them to get more of a visual understanding
no this is what I'm talking about
block matrices
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Can somone explain how to find domains with an example
you set the bottom equal to 0
you set the bottom equal to 0 to find the asymtotes where x does not equal
Is dis a domain qiestion?
what does that equal?
2+x
How it become negative
finding the domains of a functions is basically finding for what values the function exists, can have values
for yours in the pic up there
as a general rule with fractions , the denominator cannot be 0
because logically speaking you cant divide something by 0. it would mean it doesnt exist
Alr so x+2 >0
so knowing that it cannot be 0, you need to find where the bad apple is, for which x the denominator is 0 so you can take it out
does it say that in the problem?
now if we go back to the function and check, indeed for -2 the denominator is 0
Pls say as fast as u can
so it would be R-{-2} the domain
R is range
poppy ur eating fr
honestly my professor explained it so bad that i had to take it into my own hands
it was honestly impressive how much sense it made once it was explained well
@full cobalt are you still around?
seems not but if you do come back basically the domain is what values x can take so that the function exists. considering that only for -2 the denominator is 0, then for any other value it will exist therefore the domanin is R{-2} or R-{-2}, in my country both are used idk about the rest. theyre just notations which basically tell you x can take any values from the real numbers set, aside from -2 ( thats what the \ or - means, its just the notation)
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The least that your venn part can be are 0 right ?
You can't have negative amount of elements in your venn
yes
??
Badly worded i meant my second sentence
Looking at your venn diagram you see that there is three expressions that can fit for oir problem
Thoses in intersection
And so you have that 27-x >= 0 so x <= 27 but for x = 27 the part with 25-x and 24-x are negative and it make no sense
So can't be this one
What about 25-x
Gives x <= 25 but for x = 25 you have that 24-x negative, which is no sense again
Lasting 24-x giving x <= 24 and here no problem with other part of the diagram
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n in the summation should be fine
you proved it for n = 1, and now you're showing that assuming the statement for case n will imply that it's true for case n + 1
this proof looks fine to me
yes
it makes sense because the summation doesn't use both n as an index and a upper bound
the other side of the = sign doesn't matter
yes, it's fine
.
P(1) is true, and P(n) => P(n + 1), so you're good! 
you too! 
you may close the channel if you're done 
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would x just be 7?
i proved abd similar to dbc (aaa)
Then how did you conclude x=7?
since i provced that the angles inside are equal and the exact same
idk if im doing stuff right
thanks for the help
.close
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hey
ask your question instead of saying you need help.
send the question anyway and try your best to translate it
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Hellow. I'm trying to find the general solution for number 4. The problem suggests we use e^2i instead of cos(2x) and then pick the real part of the result only. I'm unsure about the form a particular solution should take.
Should it take this form?
so, I see what you're trying to do, however, you've got a non-homogenous linear ode and so you'll need to solve for two different solutions.
generally in this case we would consider the homogenous solution and the particular solution. They have other names also, but thats just what I tend to call them.
so idk where I was going. But your current for of solution likely wouldn't work
you're welcome to try it
but really your probably going to have to control the exponent factor as well
also, you will probs need a coefficient infront of the x^2
@brittle harbor Has your question been resolved?
I already found the general homogeneous solution
Right, I forgot it
What do you mean? Why this wouldn't work?
Because you don't know how the exponential 'factor' is going to behave. Why is it going to be 2i? Right?
And maybe you have other info which can tell you that it does. But I don't think it does, just from gut feeling anyways
The point of using undetermined coefficients is that you don't know any coefficients of the x terms
Yeah, my bad. I don't know what I was going on about. I don't read your question fully. Sorry bout that.
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did you get it into polynomial form
don't we take x^3 as LCM?
nahh, our teacher js dumped this equation and she didnt even teach a single thing cause she was frustrated, she didnt even teach it bru
I think you open the brackets and then take x^3 as LCM
do we need to find the roots, what do we need to do
But then we don't get
we need to factorise it:/
ohk
i dont know a single thing bout this
u need to do this, and then find a factor by trial and error
is this equal to 0?
yea long division but it should be equal to 0, if its not idkđ
Factorize this? Hmm...
yea
just set it equal to 0; write it in polynomial form and maybe hopefully guess a root
yup
alrr ill try
neon
this might not work sry
,w solve -2x^5 + 10x^4 + x + 11
yeah there's nothing clean here
either we're missing context or your teacher just forgot to give it to you
yea ig
Or the problem isn't to solve it. This isn't an equation, it's only an expression. Is the task to put into a single fraction?
yup
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.
I'm seeing 2x² + 10x + xâťÂ˛ + 11xâťÂł.
bruh I asked you at the start
i already sent the orignal screenshot
Without context
our teacher just sent us a bunch of explressions and nothing more, she told us to factorise it, there was no context, just a word file of which I sent a screenshot
i dont have any context
"she told us to factorise it"
How did she tell you this? Verbally? Or do you have written instructions?
verbally, yea
If written, may we see these instructions?
Ok... Do you remember exactly what she said? Verbatim?
Alternatively, if this is not the first one you have solved, can you provide us with a prompt-solution pair?
its was something like, "you need to factorise these equations", nothing more, just this
its the first one
expand the algebraic expression first
Then I'm afraid I'm at an impasse here. I don't know what is actually being requested in this problem. Perhaps someone else is better able to read the tea leaves than I am.
uh huh, done
i js need someone to teach me from scratch
Like if you don't know factorisation why would your teacher give a polynomial of power 5
idk man
They should start with 2
The expression you gave simplifies to a quintic. Famously, quintics do not have general solutions, and I trust the other users who have been helping you up until this point that this quintic does not happen to factor nicely.
There is nothing you can do from here without breaking out high level mathematics.
Yup. It's a quintic omitting the x³ and x² statements.
The 11 term is the thing that's the problem here-
so, i just dont have an answer to it?
I double checked and this quintic indeed does not have nice solutions.
It is not factorable.
alright
At least not without introducing a specific special function called a "Bring Radical" and even then your solution is going to be extremely long and tedious
You can attempt to factorize it as (-2xâľ + 10xâ´ + x + 11)/xÂł. But you'll have to use a lot of little tricks to get anywhere farther than this.
-2x^5 @reef marlin
Right.
okey thx everyone, now i gotta close this channel
Alright, good luck with the rest of those questions (if there are any left)-
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Sorry! đ
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in this diagram, i have to find lenghts BX and XC
i dont know where to start..
do you know what is sine law?
a/sin(A) = b/sin(B) = c/sin(C) ring any bells?
i have already proved abc and cax are similar
U can use similar figures instead
sorry i havent learnt any of that
hm
Ratio of sides is 3 to 2
yeah yeah i know the basics of that
oh u did ab/ca?
i split the triangles into 2 btw
Yeah
triangle BAC and triangle CAX to help me better visualise
U know ax=ac
yes yes
oh wait
i thought ac = ax was some formula
yes yes i understand ac = 10 = ax = 10
Oh I was just referring to in the diagram
So we know that bac~cax cause they both have base angle of 80 meaning theyâre vertex angle is 20
yep
yuh
So we can substitute those back in and get cx=20/3
After thst we also know bc=15
So subtracting cx from bc we get bx
hm im still tryna process
If we substitute the numbers we have into the ratio we have 15/10=10/cx