#help-0
1 messages · Page 869 of 1
I don't even know how to start the solution
it has this solution but I don't understand any of it
What is the "join" of two points?
the line segment, I'd wager
I'm fairly sure that I have to use the Section Formula somehow
but I'm not able to
it just leads me to a very complex solution
and no question would be that complex
god this is literally the first question
,rotate
Well, sine gives the y value of a unit circle and cosine gives the x value.
So, x = cos(θ) and y = sin(θ), so y = sin(arccos(x)).
And y = sin(arccos(x)) can be written y = ±sqrt(1 - x²).
someone please help me I have my maths exam in 6 hours 😭
it will have this topic
<@&286206848099549185>
it's arithmetic
@quartz parrot Change it into this:
= (-8 + 1) + (-4 + 1) + (0 + 1) + (4 + 1) + ⋯ + (400 + 1)
= (1 + 1 + ⋯ + 1) + (-8 + -4 + 0 + ⋯ + 400)
this is going on forever, should this end up just being 2n+1?
@rigid kiln Sorry, this channel is busy.
ig ill use another channel then
Why not just compute 1 + z + z² + z³ + z⁴?
how would i?
yeah hat is what i did
i made it into exponentual form
and then i change it to (e^(10ipi/4)^n
in which n is for each of the {1,2,3,4}
yeah
you mean the polar form?
so what i did was change it to exponential form first
in which i would be able to do the ^n really easily
and then i then change to polar fomr
I think you're saying polar when you mean rectangular
If you have it in cosθ + isinθ
Exponential form is really the polar form
Well, now that you have that, adding them should be easy
Especially since z² = i
$1+\cos\left(\frac{5\pi}{2}\right)+i\sin\left(\frac{5\pi}{2}\right)+\cos\left(\frac{5\pi}{4}\right)+i\sin\left(\frac{5\pi}{4}\right)+\cos\left(\frac{15\pi}{4}\right)+i\sin\left(\frac{15\pi}{4}\right)+\cos\left(\frac{10\pi}{1}\right)+i\sin\left(\frac{10\pi}{1}\right)$
BorutoEyePower
wait why is z^2 = i?
this is when i changed into exponential form to easily evaluate or i could of just skipped and use de`moivre theorem
@placid zinc anything i can do, or is this just too much, i could of easily simplify it with an easier step?
it's a geometric serie
So demoivre and exponential are really the same trick
That is, if
z = e^(π/4)
Then you can square both sides to get:
z² = e^(2π/4) = e^(π/2) = i
gcf (7, 15)?
7 is prime
wait how did you reduce z = e^(pi/4)
oh yeah
so what is the method you are thinking
so when it is multipled by powered by 2, it would be an imaginary number only
so z^4 would be -1
yeah
and z^3 = z^2 * z = i*z
because in a circle, it is on the left hand side of the complex plane
right
okay thanks this helped alot
or you can just write the sum as (z^5 - 1)/(z-1) = -(z+1)/(z-1) since it's a geometric serie, it works too
at some point you have a bit of calculation you have to do
is there any way in which i can visualise e^i*degrees
desmos doesn't seem to offer anyway since i = root(-1) is invalid
yeah, so it essentially a circle basically
then you just have to visualise the angle
the distance from the origin
okay, thanks, this helped alot
so its 400+(8+4+0...+400?)
i dont know what to do with the other braket side
wait
so id get 400+(5050-12)4
so I get 20552
can i have some help <@&286206848099549185> ive needed help for 3hrs now
im 15 and im 1 question away from finishing doing 5hrs of maths
i just want to go to sleep, can someone help me on the last question, please?
@quartz parrot No, there aren't 400 terms.
is this right
@stable dune Sorry, this channel is busy.
@oak chasm can u help me out bud?
@wispy wing First, find the coordinates of P. Then, find the angle pointing at P from the origin. Then, the slope of the tangent is perpendicular to that. Now you have the slope and a point on the tangent line, so use point-slope form.
theres a graph?
Oh, you don't need to find the angle.
You can just find the slope from O to P.
Take the perpendicular slope to get the slope of the tangent line.
Then you have a point and a slope.
i hate to be annoying but i dont know how
Which part?
just the whole thing in general to be honest
OK, so x² + y² = 90, right?
yes
10?
Why do you say 10?
sorry 9
@alpine sable Sorry, this channel is busy.
@wispy wing So, what does the problem say about whether y is positive or negative?
it doesnt say anything
Yes, it does.
- ?
Why?
Because P has a x - coordiante?
It would be better to sleep and then do the problem.
It's possible to become too tired to do problems or to work your brain so hard that you can't think about anything difficult.
The solution is rest if that's possible, not finishing the last problem right now.
You'll get better results and learn more from it.
ive got physics for tommorow though
Yes, but like you said, it's only one problem, and it's like a five minute one. You can do it in the morning if you have time.
can we just finish it quickly now?
i dont want to go to sleep thinking about it
@oak chasm im sorry if im being annoying
but i really want to get it done
No, it's not that, it's that we're supposed to guide you and it's more like I'm doing it for you.
its not 5 min for me, ive not even learnt it
marc
@zinc cosmos https://math.stackexchange.com/a/265700.
is there a link i can have on how to learn mine?
Point slope is easier than their slope intercept form, though.
z is unkown, but they want us to expand and simplify
but is there a way to do this a more smarter way than just bruteforcing it?
@rich basin idk what you mean smarter, I'd just multiply it out
There aren't any tricks in this one in particular
like how did you expand it?
Yeah, it's just what you do normally, I don't see any ways to "quickly" do it
Like idk, do the right 2 things first
You mention z is known, what is it dyslexia moment
do the last two brackkets first
do you know sum and difference of cubes?
look
what about them in here?
two key observations
i don't quite see it
yeah i got (z+2)(z^2 -2z +4)
which looks like (z+2)^3
but then how do i get this down?
you sure?
isn't it?

(z+2)^2 = z^2 +4z + 4
yeah?
z^2 - 2z + 4 \ne z^2 + 4z + 4
when you multiply it out you get z^3+8
yeah
what's the problem then?
i just learned something
about how to fast multiply this
which i never knew
so when you have something that have powers that are negative of each other
it completely removes the powers
Why?
yeah
I'm studying french rn 🙂
very cool
@rich basin I'm still weird about the (z+2)^3 comment and I want to make sure you meant z^3 + 8 or that it was just a mention that it looked kinda like (z+2)^3
as z^3 + 8 is not (z+2)^3, it's z^3 + 2^3
actually there's a famous theorem that goes like (a+b)^3=a^3+b^3

but unfortunately it only holds for sedeonic a,b
kirby, veux-tu parler français avec moi?
eh , pas maintenant
I actually meant the (a+b)^3
Like if you take a look at the following equation doesn't this look like (a+b)(a^2 -ab + b^2) ?
because (a+b)^3 = (a^2 -ab + b^2)
what do you mean here
(a+b)^3 = a^3 + 3a^2b + 3ab^2 + b^3
Vieta's formulas would be kinda fast. But it's the same you would get with direct expansion...
the factorization you had was the complete factorization of z^3+8, since you had scaled up roots of unity
the equation of any circle is: $(x-a)^2+(y-b)^2 = r^2$ where the center is $\Omega = (a,b)$ and the radius is $r$
Salah
Thank you!!
I've looked at explanations of significant figures and it doesn't quite make sense to me
how many significant digits are there in 1.008?
4
1.800 has 2?
4 and 2
If there is any N front of the zero then You include it
3
i wanna say 6 but that sounds wrong
i mean, it feels like the entire number conveys information
@wooden crag I think there are three basic rules for significant digits
The first one is that any non zero digit is considered a significant digit
Then if there are any zeroes between non zero digits, then you consider them signififsnt too
If $n=pq$ for two primes $p$ and $q$. Then, $\phi(n)=(p-1)(q-1)=70$.
$\phi(n)=n\prod_{p|n}\left(1-\frac{1}{p}\right)$
Euclid31415
There is no need of that.
marc
That's what I did
marc
No. I assumed n=pq first and then wrote phi(n)
Oh no I didn't notice
Then, if $n=p^aq^b$ then, $\phi(n)=(p-1)p^{a-1}(q-1)q^{b-1}$
Euclid31415
I think you just have to consider different cases and check...
thanks
help?
what have u tried, and what do u need help on?
i suppose a hint could be use logs
what is the two possible roots of √36?
I tried dividing 40 by 200
so 5.7^x =0.2
Most would say it’s $\pm6$ and I guess that works
The step where absolute value comes into play is often skipped
lexitorius
then is -6 counted as a root of 36
It shouldn’t really be but usually yeah
ok thanks
if you do ${log{5.7}{.2}}$ in a calculator it should work
Swag369
idk latex properly lol my b
what is latex
its the fancy math typing
you knoow how the tex bot had the +/- 6
thats written with the $$
$\log_{5.7}(.2)$
Mosh
also it said to use log not log_(5.7)
value of √25/36?
Oh right i got it thanks
What can't you plug in?
Can you plug in -100000?
You're right, you can't plug in 1,√2,-√2
You can't plug in even more than that, though
Number under a square root can't be negative.
x + 1 ≥ 0
Those are your discontinuities. Everything else is continuous
[-1,1) U (1,√2) U (√2, inf)
should be closed on -1
based on vector addition, what is a+b?
we know a+b is line segment AC
now if we have that OC starts at the midpoint then we need to scale this (a+b) by something that would cut it in half
thus we get 1/2 * (a+b)
did i make a feasible problem based on the figure on the first picture?
(i only used the left figure the right figure is only optional)
oh right that make sense, thanks
Guys please I need help
If this is a legit exam, we cannot help you with exams
@knotty badge is this a timed graded test?
It’s not a “legit” exam
"legit"?
It is a test indeed
But it’s not graded as a test
It’s practice and it’s still graded
And it’s stressing me out
I just need to know where z alpha button is on ti-84
So what's the ruling on helping out this person?
I really don’t need help on the question I just need to know where that button is
That’s all I need guys
I'm not even sure if that button does exist on a calculator. If that's probability and stat, and you need z, there's a z table that you can look up
How would you do this, I get X>-7 but for some reason I don’t get how it’s also X<5/2
What's the full question?
Hey if you had round to fourth decimal and your answer is 0.4469 would it now be 0.45
So 0.447 would be correct right
How many does this value have?
You just need to find what x is
0.4469=0.447
It says 4 decimal places, you start counting after the decimal point
I don't think so, because it looks like those values are what makes the denominator undefined
Can anyone tell me how to calculate solstice equinox?
I'm trying to understand the formula I have to use.
Is a number unusual if it’s less than 0.05 or greater
That’s what your mean’t to do with inequalities…
Bring the 1/(x+7) to LHS and you get\\$\frac{2}{2x-5}-\frac{1}{x+7}=\frac{2(x+7)-(2x-5)}{(2x-5)(x+7)}<0\\\implies \frac{19}{(2x-5)(x+7)}<0\implies \frac{1}{(2x-5)(x+7)}<0\\\implies (2x-5)(x+7)<0$
Euclid31415
how do i approach this question?
If cos(10)=sin(θ)and 0<θ<90, then
θ = ? degrees
What is the complementary of 10 degrees?
$x^2 -2(y)^2 = 1$
solve pls
Aldrich
ans x=3 y=2
you can use a trig identity with the complement angle, yeah
Its even in the name. "complementary sine" or "cos"
help a mf out
Ohh thanks
sin80?
Yes! sin(80 degrees)=cos(10 degrees)
it says my answer is wrong, it wants it in degrees so i did sin(80) on the calc and got 0.98
oh thhe key said 0.8
ok
thats nice but where do we get an integer solution from?
0.8??
dead game in NA, i bought the game and tried it for like 5 minutes and refunded because the movement is so slow
feels like the map has 0 gravity
yeah i know its popular outside
Valorant ?
That was going HOT
It's all like CS : GO
Pell equation
eyes going bad x.x
Same here.
did anyone get sqrt(a)/b
can someone explain why theres a - on the numerator?
it means the result is negative unless the result is negative and therefore positive, i think
<@&286206848099549185>
to find a coterminal angle u just add/minus 360 right
Yes
anyone help me do (b)
use the formula sqrt(x²+y²)
well, you know that BD and DC are the same length as the other vectors since it is a square
and since it's a square BD and DC forms a 90 degree angle with the other lines that are connected to it
yeah
so
i got it
how would you find the intersectiion
would that jsut be the mid point for (e)
Okay i got it
since x,y in the two equations should be the same
if you're trying to find the two point
and correct me if I'm wrong about this
but if you're just trying to find the two points that divide DE into 3 equal parts
then you can just use the equation to find the distance between two points
except instead of knowing the second point, you have to use the slope and the distance
what equation would that be?
I can't really see images dammit
is a point that is on the line DE
ok so
you have the equation of DE
in the form of y=mx+b
then you have then equation to solve for the distance
not sure
does the order of these symbols matter?
like could I do L | D' and it would be the same thing?
no
im seeing it for the first time right now im not quite sure what it means to be honest
I'd assume you are right
P(A n B) = P(A | B)P(B) is kind of circular here lol
I think what it's supposed to mean is just P(AnB) = P(a)P(b)
because if we're just talking about intersection, then it doesn't have to be conditional
this is the solution for (e)
but i can't put in for some reasons, the screenshot?
okay now it works
but why is it that the they change the vectors to become (b-a)
and not (a+b)
what happend to this : f(x) = 4x+1
to be this : g(x) = ( 4x+1 ) + 3
i need some help 
Isn't that g(x) = f(x)+3?
no i mean the move
Offset 3 units to the right
Offset 3 units to the top
Horizontal stenosis with a factor of 3
Vertical dilation with a modulus of 3
one of this
yeah
what would +3 look like
suppose i had a bunch of points on the graph
i +3 to all of them
what happens
ssoooo whats the answer from here :) ?
@hardy gulch
Maybe it's a symmetry type thing?
Like the triangle formed by OP and the x axis seems similar to the one formed by OR and the x axis
Which makes me feel like it would be -3+4i or something.
But that's just a vague guess.
@clever folio you got it somehow, but i don't know how multiplying it by i makes it like that?
isn't it rotating by 90 degrees anti-clockwise
when multiplied by i
I looked at the geometry being shown
Take the perpendicular to the x-axis and P and look at the triangle formed. It is similar to the one you'd get if you take the perpendicular to the x-axis thru R
yes, multiplication by i corresponds to a 90° ccw rotation about the origin.
Using complex numbers will probably be a lot more elegant and easy lol
Would what I did be equiv to multiplying by i^2?
Nah wait nvm lol
i mean this question mentions complex numbers directly
I will be back, I have to go for something really quick. Be back
okay i am back @clever folio
I think you are just mixing something up when you mult by i is all.
It seems like it works when you do that.
like aren't they perpendicular once i saw it?
so can you go with your method?
@clever folio what did you exactly do to find that solution?
Make two triangles by drawing vertical lines from P and R to the x axis
Notice that these two triangles are basically the same but one is rotated and translated
yeah
So the lengths correspond in such a way that to get from the origin to R you would go left by 3 (so -3) and up by 4
It's a more complicated solution than just multiplying by i
wait so how is the triangle rotated?
is it triangle rotated by the origin?
or is it from the placement?
It's rotated and translated
Rotated from what reference?
Rotate the OP triangle I mentioned clockwise and shift it left
Seeing as this is not the solution the exercise intends I doubt it's worth worrying a bunch about lol.
what i'm confused is what axis are you using to rotate them?
I'm not sure how to better explain rotating a triangle clockwise. :/
You see the op triangle I'm talking about right?
So rotate that triangle clockwise until P is on the x-axis lol
okay
Now shift that triangle left until its hypotenuse lines up with OR
The vertical and horizontal legs give you the coords of R
so let me assume that the triangle is OPR?
with the triangle or with the entire box?
Call the pt on the x-axis B or something. This triangle would be OPB or whatever
if triangle, what triangle would the points be?
Just told you the pts
No that is not what I said.
See this
is it a right angled triangle?
Yes it is a right triangle
yeah that is what i was thinking about
Ah okay
Yep basically
okay
Rotate it clockwise and shift it left til it lines up with OR
yeah
You know the vertical and horizontal legs of the new rotated shifted triangle
They tell you the coords of R
Yeah looks right
oh right, that is pretty good. Thanks
what would exactly be the complex nubmer way of looking into this?
Multiplying by i
It'll be way simpler than this lol
i(4+3i)=4i+3i^2 =4i-3=-3+4i
It gets the same answer in much easier way.
so how you identify that they are peerpendicular
is it through using the geometric theorem, that bisecting diagonals within a square are perpendicular to each other
forming a right angle triangle
You mean the two numbers -4+3i and 3+4i?
yeah
I'm not exactly sure I know there are formulas and stuff for it but I haven't dealt with complex numbers in a while
okay thanks, this helped alot
I think they are orthogonal (perpendicular) when the complex dot product is zero. So that would be (a+bi)f(c+di)=0 where f stands for taking the conjugate.
Don't quote me on that though lol.
Well, real part of that product=0 implies perpendicular
Hello guys I need help can anyone help me ?
send the q
Let OA = a and OB = b.
Find vector of OD and then ratio of OF:FD and EF:FA
coord bash wud be a fun way to do this
have you ever encountered the min() function before?
No I don't remember such a thing
min(x,y) is equal to whichever of x and y is smaller
for example min(420, 69) = 69
this problem tells you that in fuzzy logic val(P & Q) = min(val P, val Q)
Oh ok tbh honest I wasn't expecting it to be that simple ... thank you so much ... I kinda feel stupid now :)
So I got a equal what should I do there's no maximum
Or minimum
can you please show me that, i tried using z = 3-2i and iz = 3i+2 and when i multiply them together, i get Re(iz^2) = 12
I meant for non-zero complex numbers $z_1$, $z_2$ they are \perpendicular iff $Re(z_1\overline{z_2})=0$
Euclid31415
aren't all real numbers complex?
Yes. They are a subset of complex numbers
isn't this a non-zero compelx number?
I didn't understand
like if you take a look at 3 -2i there are information about the complex number already, so it wouldn't be zero
Yeah it totally applies here
See that line over the top of z2 here? That is taking the conjugate
Okay, aren't conjugates just refelctions?
Yes they are reflections about real axis
so if you have a position vector for them, and draw a line to them. They would just form a rombus
$\overline{3-2i}=3+2i$
Euclid31415
We just flip the sign of imaginary part
but then perpendicular is more visualised through geomtry
This fact holds
That's just an opinion
I mean, in order to start with this you need to first prove it with something you know
which is geometry
It starts with Euler's formula and why multiplication by complex numbers corresponds with rotations and scaling
yeah
oh right i get it
i could start visualising it in euler's formula
okay thanks
Hi i dont know how to do these questions
The lesson you're training on is transformations of functions, right?
yes
Okay. Let's see c)i). The way it's displayed can be a bit confusing, but when you multiply both sides by 2 you can start to understand what you're supposed to do.
y = 2h(x). Which means that for each input of x, you'll get twice the output of the original function.
So in the original function, if x = 0, y =1. In this newer one, if x = 0, y = 2(1)
If you apply this to all points, you'll end up with a curve that's stretched vertically by a scale factor of 2.
hi can someone help
@alpine sable so do i multiply y-coordinates by 2?
Yea
I have this cheat sheet that my teacher actually gave me in case I'm not available to explain in detail the rest
It seems you're just doing the stretches now so don't worry about the rest.
But if I'll explain the horizontal stretch, when here in c) ii) it tells you that when you enter an X into the function, you'll half that X before you input it.
Originally X = 2 gave you Y = 1, but here since you half the X before adding it in, you'll need the X to be 4 to give you the same Y = 1.
what would i be dividing the x-coordinates by?
Actually you'd be multiplying them by 2.
Since you need twice the X to give you the same Y.
It's like someone weakened the X and you're giving it reinforcements.
But don't worry it's usually only the f(x) changes that are counter-intuitive.
The sum of two numbers is 13. Twice the larger number is 8 more than 4 times the smaller. What are the numbers?
What does the 8 more than 4 times the smaller mean?? 😖
Yep
Alright thanks
nn
can someone help answer q 74 and 76
f(g(x)), you replace the x in f(x) with g(x)
@alpine sable wait for questions like y= h(x/(random number)), would it mean you always multiply x-coordinates by 2 since you need twice the x before halving the fraction to get 1?
You multiply the x by that number
In this case it was x/2 so you multiply it by two.
If it was h(2x) you divide by 2
Really just do the opposite of whatever he does to the x
But I think you got the general idea right.
ok thank youuu
what do the square brackets mean?
nothing
yesss
tyty
how is my answer not correct, shouldnt the product rule be used here>
That last "u" should have been "c"
hi guys how do i differentiate this?
You bring -2t behind t and multiply it by t to which gives you (-2t^2)e and then you subtract 1 from the power which gives you a power of -2t-1.All together the answer would be s'=(-2t^2)e^-2t-1
thank you 🙂
ohh i can apply properties of log for e also?
Hey there,
I need to find the value of sup(A), inf(A), min(A), and max(A). Or - prove that it doesn't exist.
My see that there is not sup(A) and max(A) but I don't know how to write it down and prove it.
I showed that 2 is inf(A) and min(A), but I couldnt continue from there.
I am sitting on this one for hours... any clue?
No! This is incorrect!
Using the product rule, $\frac{ds}{dt} = \frac{d}{dt}(t)e^{-2t} + t\frac{d}{dt}(e^{-2t})$
JarrGarde
This should be alright, although I am a bit tired
how do you find the bearing?
i See
what did I do wrong when differentiating I used the power rule (nX^n-1)and simplified the expression.
Yes and then we get $\frac{ds}{dt}=e^{-2t}-2te^{-2t}$
Euclid31415
That power rule is for differentiating x^n with respect to x… and not for things like n^x
Oh why is the order switched around in this case?
You treated e^{-2t} as power rule…
And moreover it has an extra “t” multiplied on the outside!!
hello
If you have a limit function, where f(0) is not defined
the assignment states that f(0) = 1 because of this
and then they ask me find f'(0) and f''(0). not sure how to begin this assignment..
Would be helpful if you posted the question...
Why is the marked thing there? Like how did we get that its equal to the right hand or left hand side?
How do you find x?
You can work out how many degrees total there are in a 5 angled shape by dividing it into triangles and using the fact that the sum of the angles in a triangle is 180 degrees. That should start you off at least
thanks
I had a question on a number theory exam.
P=110322353973061799
P contains a five character HEX subliminal message.
Using n=10007 as the base extract the five decimal coefficients of the polynomial generated by n that P represents.
Not expecting to get a full answer but maybe some pointers to how do I go about solving this.
Hi, this is a pretty dumb question but I can't seem to figure out where I went wrong?
I am given this equation and Im trying to find the roots
while not knowing what y is
So I found this as a root
but the actual answer is
What gives?
And delta (the stuff under the root idk what it's in english) would be 4y+8 which the correction confirms
Nvm im rlly dumb
helppp how is this wrong? if tanx = 2t/(1-t^2) then isnt sinx the value on the numerator @-@?
hi
i have an exercise
given the are of circular sector= 16pi find the perimeter of this sector
Tan is undefined when cos is 0. Therefore, tanx = sinx/cosx
So yes, sinx is the value of the numerator
n=25
How do you algebraically prove that sqrt(2) is irrational?
then y my answer wrong T_T
how did you do it
What does it say when you switch the two?
I'm very sure that sinx is the numerator
You can find the radius of the segment by square rooting the 16 and taking the pi away and then you do pi times 2r which is 8 pi which is the curve part of the segments length then you just add 2r to 8 pi for the 2 radius length lines attached to each end of the curve and go into the middle of the circle
Oh wait I think I forgot about the angle part with fetur/360
it says that its wrong :(
🤨
Yea idk then 😂
are you sure that the radius is found that way. I think the formula is S=(n*r^2*pi)/360
where n is the degree of the angle
Yea your right I forgot about the angle part at the begging sorry 😅
Sounds like a problem with this thing you're using. I don't know why does it error like that
no problem
Does it count brackets?
i'm asking on #geometry-and-trigonometry any help is appreciated
use rules for manipulating det
let me get a good reference for you
Learn about Properties of Determinants topic of Maths in details explained by subject experts on Vedantu.com. Register free for online tutoring session to clear your doubts.
There we go
Let me know where you think we should start. Hint: transposing the original matrix means its det is still = 3
We can also swap rows and columns without changing the value of the det
except in sign !
3 -> -3
etc
@orchid python
does sin(a+b/2) have a formula of its own?
The standard formula for sin(A+B) is: sin(A+B) = sin(A)cos(B)+cos(A)sin(B) Now sin(-B) = -sin(B) and cos(-B) = cos(B), so sin(A-B) = sin(A)cos(B)-cos(A)sin(B) So: sin(A+B)*sin(A-B) = (sin A cos B + cos A sin B)(sin A cos B - cos A sin B) = (sin A cos B)^2 - (cos A sin B)^2 ...using the identity (p+q)(p-q) = p^2-q^2. = sin^2Acos^2B-sin^2Bcos^2A =...
Good day! I'm trying to understand polynomial factorisation in the complex set then coming back to R set. say for example we have $P(x)=x^4+x^3+x^2+x+1$ what do we do in order to transform it into $z^2-\alpha$ to solve for the complex roots. for P(x) our prof multiplied P(x) by (x-1) to get $z^5-1$ and then find its roots. How do we figure out that?
nas
@subtle seal
One way might be a geometric series:
1 + x + ... + xⁿ = (x^(n+1) - 1) / (x - 1)
In general it's a common factoring trick you'll get used to:
(x - 1)(1 + x + ... xⁿ) = x^(n+1) - 1
excellent thank you! that makes sence
I suppose this is solely for polynomials with 1 as the coefficient for all its terms correct?
Yeah there's no similar trick
Well, if they're all the same coefficient you could factor it
also after I find the complex roots for x^(n+1)-1 how do I rewrite p(x) as a factor of those roots? do I need to divide p(x) over (x-1)? for the final result
The roots of x⁵ - 1 are
1
e^(πi/5)
e^(2πi/5)
e^(3πi/5)
e^(4πi/5)
@subtle seal
If you take any of those to the power 5, you get 1
Does someone know why the truth table of logical implication is like it is?
that makes sense
why is it b ?
Or, sorry, double all of those exponents
so $x^5-1=(x-1)(x-z_{1})(x-\overbar{z_{1}})(x-z_{2})(x-\overbar{z_{2}})$ Now how do we get p(x)?
I messed it up haha
nas
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
the other z1 is the conjugate
don't know how to add the bar in latex sorry xD
do we divide it over (x-1) to get back to p(x)?
z1, -z1, z2, -z2 are all of the roots we've found
So you have the factored form of P(x) right there
what about the (x-1) that we initially multiplied by to get x^5-1?
I'm confused. Are you starting with P(x), or trying to find P(x)?
Starting with it and trying to find its factorised form
z1, -z1, z2, -z2 are all of the roots we've found
So you have the factored form of P(x) right there
Note that multiplying by x - 1 put it into a form that gives the roots easily
I see the root of x-1 is irrelevant
perfect! thank you very much. you cleared up a lot of confusion
Np! Feel free to ask if you need anything else
If the x was negative the graph would be decreasing
Now if you were to plug any value to x you should get a y value that lies on graph a
Need help with derivations
Don't know anything about derivations
May someone help me understand a question I have about a math problem it's kinda confusing
It's: If RS= 23-2x , ST = 9x-5 and RT = 39 Find RS
Sure
I have edited it in the message :D
I can send a pic if that helps at all :3 but idk if It should adds to 39 because it's on a line yk and the line total is 39 so yeah
homogenous systems of linear equations are equations which lack a constant term, hence the zero vector is always a solution.
the trivial solution is the zero vector.
hence you want to find the values of a such that the only solution to this system is the zero vector.
@orchid python
what would be positive?
I don't get your question to be honest
6(-1-3)(-1+2)=(+)(-)(+) so
But that one is decreasing graph right?
Which is contrary to what I sent above
no because -1 is not in (-infty,-2)
Loool, I am a dick for sure
Thanks @warm brook
I need to describe a class of sequences that satisfy this condition on the image. Like is it convergent or not, is it fundamental or not and so on. I guess that all x(n) , n > n(epsilon) don't belong to epsilon neighborhood of point a. So can I say that this sequence is unbounded?
I think no because the number of columns of the first matrix does not equal the number of rows of the second matrix but I am not sure
Yeah it aint possible
What's the area of this ?
Do you know Pick's theorem?
yeah
I have an answer but i'm not sure
I think it
Use it, another way would be to construct a square, and find the area of that square, and remove the three other triangles, let me make an image
What did you get
That looks good
you sure it's 14 ?
Yes, substituting i=12 and b=6 into the formula gives 14
should that marked square be there or not, because I have notes saying it shouldnt and im confused
I think it should be there
yeah the square seems fine, but im not sure where the (x+2)(x-1) came from
How can i solve this w/o l'hospital
13 pls
d
Here’s a (big) hint:
[\frac{f(ax)}{g(bx)}= \frac{ax}{bx}\cdot \frac{f(ax)/(ax)}{g(bx)/(bx)}]
kirby
substitute f(ax) and g(bx) for sin(ax) and sin(bx) respectively where a=7pi and b=2pi
X-sqrt(5) = 0
Therefore x = sqrt(5)
Also:
x + sqrt(3) = 0
Therefore x = - sqrt(3)
S.S = {-sqrt(3),sqrt(5)}
So d is the right answer
ah thank you so much
@shut temple yes, it’s pretty clever, but for things like this, i’d just recommend putting it into a form of a limit that you already know the answer to (if possible) then proceed
Is that long division?
The calculator will perform the long division of polynomials, with steps shown.
Here's a step-by-step solution
im getting the same as this
but i dont understand the bottom part
Retrace the example problem here, it might help you understand the principles of long division better
ohh makes sense tysm helps a lot
also does horizontal asymptote on a slant jus mean oblique asymptote?
English is not my first language, no idea. Let's ask <@&286206848099549185>
oh ok tysm for the help I appreciate it
How do i derive this
I got but i'm not sure
Didn't simplify yet
make it into an easier to use number. to start, you could change the sqrt^3(x) to x^1/3
then take the inverse so you can move it up to the numerator
then just use the power rule to differentiate it normally
Yeah i did that's what i got but everyone in the class has a different answer
what was their answer?
oh yeah
because the differentiation is linear, you could take out the 8 first
to go from d/dx[8/sqrt^3(x)] to 8 • d/dx[1/sqrt^3(x)]
Hmm
Oh so derive does mean the same thing as find the derivative of.
Yes it does
yeah that is the way
8 • d/dx[1/sqrt^3(x)] then becomes 8 • d/dx[x^(-1/3)]
Sorry I was unsure of the word so I didn't help
It's okay
You mean -2/3?
1/3-1 is -2/3
its -1/3-1
so its -4/3
because when you move the term from the denominator to the numerator, the power is inversed
you get it?
np
I don't really understand how to do this. I'd know how to do it if the 5^(sec(-5x)+1) wasn't there or if it was only that but I don't know how to do it with both of them
Does u=sec(-5x)+1 not work?
I have not done any calc in ages so I could be wrong tho lol
Yeah it should work
That makes sense lol
Try u-sub
You sub
what is X in this case ?
Did you finish the last problem with det?
Sus
I guess it's a shorthand for "do it for both +inf and -inf", since the limits differ
For +inf it's +inf, for -inf it's 3/4
Well wouldnt the limit not exist if it didnt approach the same value
Wait, the other way around
I would imagine it would have to approach the same value cause its one limit
It grows linearly when approaching -inf
3^n is the number of n-letter words
And n can only go up to 4
_ means that any letter can occupy this space
1-letter words have a form of _, 2-letter words _ _, and so on
For each _ underscore you can choose one of three characters
Let's create all one-letter words in this language:
A, B, C
Let's create all two-letter words in this language:
AA, AB, AC
BA, BB, BC
CA, CB, CC
When creating 2-letter words, you fill each gap in _ _ with an arbitrary letter, A B or C. You can choose the 1st letter in one of 3 ways, same goes for the 2nd letter, they're independent
Can you elaborate on your problem a little more?
I assume that all operations in ~code~ are O(1) - then the function itself is O(1)
I want to know why they are raising A,B,C(3) to the power of something?
Channel busy, #computing-software #numerical-analysis .
Power of 3? You mean 3^whatever or whatever^3?
Yeah.
Which one?
1st.
Alright, let's create a language with a maximum of 4 letters, and the letters are {A,B,C,D,E,F} this time. How many 1-letter words can you create?
Channel busy and which AoPs book is that?
uhhh geometry
Hmmm.
chapter 7
That fucking chapter made me quit that book.
can ya help?
Ancient Greeks sure had it rough :P
There should be.
alright so thats a no for help right?
alright ty
That's right. You have only one space for a letter, so you have 6 choices
xD.
What if you had 2 letter words?
Hint: 2-letter words in this language are just a concatenation of two 1-letter words
How did you arrive at that conclusion?
That's right
Ahaaaa.
You choose a single letter arbitrarily (6 choices)
And then you choose another letter, arso arbitrarily, another 6 choices
Not yet!
And sorry for being dumb and typos, it is 2:00 AM and I am sleepy lol.
No worries
Well let us leave this channel cause within like 10 minutes 2 people wanted this place.
disappears into a fine mist
