#help-38
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in which matrix?
the first 3 columns are pivot columns
only the augmented column is not
so since EVERY column is a pivot, theres one solution
as long as every column except the augmented column has a pivot, yes
for #1, every column has a pivot, but theres a row entry on the last row that makes it inconsistent so thats the problem
oh wait
last column is pivot
i see isee
And for #3, the last column (before the augmented one), isnt a pivot, and theres another row that isnt a pivot. makes it an infinite solution.
Would -2, 3, and 4 all be free variables?
no
ah
only the non-augmented columns without pivots are free columns (corresponding to free variables)
So which would be a free variable
x4 is augmented onto the other matrix right?
so would -2 be the free varaible?
no, x4 is not augmented
oh boy
2 steps forward, 10 back
Okay explain to me one more time what an augmented column is, and what would be the non-augmented coulmns
please
oh wait
the augmented coulmn is the last one including 1 and -1. as that was put onto the matrix?
ok ok
the text just calls it the "last column" but i don't find that very descriptive
now the non-aug column is 3, and 4 as it doesnt hae a pivot in it?
the non-augmented columns are every other column
oh i see
i see i see
Now how do I go about figuring out waht the free variable is from that?
The free coulmns are the ones without pivots
Can I think that if theyre a free coulmn, each variable in that coulmn is free?
each nonaugmented column corresponds to one variable
so column 1 corresponds to x1, column 2 corresponds to x2, etc
mhm
x2 and x4 are free as they arent pivots
So does that mean each entry in the variables x2 and x4 are free variables?
x2 and x4 are free variables as they correspond to free columns. the numbers in the column aren't variables, they're the coefficients of that variable
i see i see
So if someone asked, what are the free variables in this
And by definition, a free variable (or coulmn) is a column with no pivot
Would I say, x2 and x4 are my free variables
columns 2 and 4 are your free columns, x2 and x4 are your free variables
ah
free columns correspond to free variables
i see
also when they said, "The last column is not a pivot column, and some other column is not a pivot column either.". did they mean the augmented column is not a pivot column
i think i was mixing it up with x4 when they were saying last
whenever this text says "last column" they mean augmented column
ok
everything has clicked, thank you so much
I'm about to go attempt my homework, do I have your permission to ping you in that channel if I come across a question, as your explainations are really good? If not thats okay also, i know its busy
Im gonna close this channel
Also is there anyway to like download the transcript of this channel?
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Anyone know where I can start for this?
looks like De Morgan's law
think about how the Right hand side can be reexpressed using De Morgan's
ugh start by picking better symbols
@pseudo fossil Has your question been resolved?
but I need to show that the left is equal to a bunch of the things on the right that eventually leads to what they want
You can start from either side
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oh!
but it's usually easier to simplify the right side then to think of what to do on the left side, so to get to the right
I'm not sure what the first simplification step is
Do you know the De Morgan distributive law?
anti-algebraist 𝔸dωn𝓲²s
yes!
Now notice what can you say about (ψ ∨ ¬ψ)
why can we just say that?
T is always true so it has no impact basically
you can do a table
A T A ∧ T
0 1
1 1
what happens?
T T
T T?
true true?
false
true
okay ya
A and A ∧ T are here logically equivalent
yea
and show it ends up being ϕ
yea
it's like whether you have x = 2 or 2 = x situation
preferably you could still start from the left and just proceed to do it backwards
up to you
yaa that's what I thought
if you know from right to left you also know from left to right
as we speak.
so that's correct then?
yes
because I knew de morgan's distributive law
it resembled that, so why not start with that
it's essentially as x²+4x = 0 why not factor here x(x+4) = 0
we basically "factored"
np!
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need help solving this by completing the square
can you use derivative
if you cant we could complete the square
yeah
could you complete the square btw
i did
thats where i got the issue
it aint working out
i factor out -4.9 from the first 2 numbers correct?
u see i factored it out
oh shit i dont think i devided b by 2 and squared it
i devided it by 4.9
thats prolly where i went wrong
maybe
csn u stil solgve it
complete this square @atomic shoal
wait
max height 42m at 2.9s
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HALP
how to solve
i still don't get it
because when i tried setting 9x^2+2 not equal to 0
it kinda gave me an imaginary number
meaning square root of -2/3
how can it be - infinity positive infinity
you dont have restrictions because of that
wait
Since 9x^2+2=0 has no real solutions
yep
That means there's no real x such that 9x^2+2=0
ah i get it
So the domain is just the entire set of real numbers ye
ah tysm
u too
i mean logically that makes sene
sense
but i cannot trust my gut feeling in math
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Combinatorics
Find the possible combination of variables
problem 1
x+y+z=6 x,y,z are whole number greater than or equal to 1
I create 6 sticks , then I have to fill up 5 spaces with 2 stars
the answer is (5*4)or(5C1x4C1) ie 20. but I cannot use 5C2
problem 2
x+y+z+a=12 x,y,z,a are whole number greater than or equal to 1
use same concept of markers the answer is 11C3. but not 11x10x9.
I CANNOT UNDERSTAND THE DIFFERENCE
note:the answer 20 for first problem and 165 for second problem are strictly correct
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What you just said wasn't comprehensible. Could you rephrase what you mean by this?
sorry
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Given that we have 3 points A B and C that don't form a straight line: M is the point where MA+MB-MC=0 (all of these are vectors)
Prove that vector V (defined by V=NA+NB-2NC) (all of these are vectors) is independent of N. Construct vector V
No other information has been given
did you switch between M and N?
No I did not
I made sure I wrote everything correctly
We have a point M and an unknown point N
Just so my English won't disappoint me again lol
so you're trying to prove that if you take 3 points who are not on the same line no matter what other point N you take NA+NB-2NC is independent of N?
Yes
I'm not sure if that is correct
It's in french but I'm sure I copied that correctly
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@dull thorn
I am done I have solved it (sorry I forgot I put my phone on DND 😭)
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how would i factorise this is there any method for it
it follows the format
Ax² + Bx + C
multiply A and C, then list the possible factor pairs (include negative factors like -2 times -5)
figure out which pair adds up to B (in which case, -11)
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I believe he wants us to prove it using intermediate value theorem, but how would i prove that the function is continous first
you can probably cite that products and sums of continuous functions are continuous
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Find the last two digits of the number $2^{3^{2024}}$
alex <3
Can someone tell me how does one solve questions like these?
This is for a math competition btw, and I'm trying to atleast do better this time than last time.
do you know modular arithmetic
i never understood it
maybe i can with a little side help though, if that's the only way to solving this?
yea i don't know how to do this without modular arithmetic
could you explain to me then?
i am familiar with modular arithmetic as we've covered it before but i just never understood how to do it, we just went through it in a breeze
So, to solve this, to find the last two digits, I would use mod(100)?
yes
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can someone help me solve this
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1
$\ln(a^b)=b\ln(a)$
;(
$\sqrt{x}=x^{1/2}$
;(
ok so 1/2lnx
i would rather you not use it, but yes, i know what it is.
when i plug in this it shows me the answer "(lnx*x-x)/2"
yes, it is.
but when i plug in integral of 1/2lnx it shows me the answer of the integral i solved myself using ibp method
so that would be ((lnx*x)/2) - (1/2)x
yes.
wait what
$\frac{\ln(x)\cdot x-x}{2}=\frac{\ln(x)\cdot x}{2}-\frac12 x$.
;(
oh
you quite literally just split the fractino.
so i solved it correctly
yes.
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True or false: the intersection of linear hyper planes is always nonempty
I believe the answer is true because linear hyperplanes always go through the origin so any two given hyper lanes must have at least the origin in their intersection
I would appreciate any feedback on this
what is your definition of a hyperplane?
We define a subset of Rn of the form H = { x in Rn s.t a^T x = 0 (vector)} for a fixed nonzero vector a in Rn
okay, but importantly, this definition says that 0 is in H, yeah? 
so in that case, every hyperplane contains 0, and so I agree with you
no problem
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\int 1/2 ln x
1/2 \int ln x
1/2 x + c
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is the answer x*(e^2θ)*sin^3θ correct?
why does sin 3θ have to switch places with e^2θ
no idea what you mean "switch places"
commutative property
it doesn't have to?
oh
why do you think so
i just looked it up on photomath
there's more than one way to do this problem
is this the right path or am i completely wrong with this answer
but i think the intention at the moment all solutions involve double integration by parts.
so am i on the right tracks do i integrate by parts the "answer" or no
i really have no idea what you mean
u said double ibp
yes
i don't know what "answer" you're referring to
so the first ibp i got x(e^2θ)sin^3θ
ok so is ((xe)^2θ)*sin3θ-sin3θx is this better
you should not have x anywhere
oh damn
this tells you the variable you're integrating is theta, not x
-(((e^2θ)*cos3θ)/3)+((sin3θ)^2)/18 better?
but how do i do it
should just show your full steps instead of the last one
ok
can't find your mistake from one wrong answer
u=e^2θ
du=0dθ
v=-cos3θ/3
dv=sin3θdθ
uv-∫vdu
(e^2θ)*(-cos3θ/3) - ∫ (-cos3θ/3) sin3θ
from this we get -(((e^2θ)*cos3θ)/3)+((sin3θ)^2)/18
im so sorry i gtg
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Hello
it’s what that monster expression is equal to.
try to factor a 2x term from the numerator and see what you get.
$\frac{N_x - M_y}{M} = \frac{-6x^3y^2 - 8xy}{2xy^3 -2x^3y^3 - 4xy^2 + 2x}$
knief
since this isnt purely a function of y we cant use this in finding an integrating factor to make it an exact DE
wdym this isn't purely a function of y?
there are terms with x in it
you learned the integrating factor method right?
if its not exact
how to convert it
$\rho(x) = e^{\int f(x) \dd{x}}$
knief
$f(x) = \frac{M_y - N_x}{N}$
knief
if this condition is met
and for the other case
we can check if $\frac{M_y - N_x}{M} = g(y)$
knief
in which case youd use $\rho(y) = e^{-\int g(y) \dd{y}}$
knief
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you can directly post your question
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didn't realize my suggestion was so controversial :p
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don't troll
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Need a hint for this problem
Polar form of a vector:
$$\vec{u}=\norm{u}(\cos\theta\hat{i}+\sin\theta\hat{j})$$
SWR
Instead of 60 degrees can I use pi/3
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Can someone help me figure this out please?
Do you know what the equation for a circle looks like?
With radius r and center (a, b)
is it x^2 + a + y^2 - b = r?
No
Because then you could move the a and b to the right to get x^2 + y^2 = (r - a + b)
So it wouldn't be well defined
Okay easier question
Do you know what the equation for a circle of radius r and centre (0,0) is?
Work it out using pythagoras
Normally taught in middle school I think so you've probably heard of it
Yeah fair enough it can be called either
Named after a guy called pythagoras
Anyway
Can you use that theorem to work out the equation of the circle?
no i have no idea
Okay
This diagram represents every point on the circle
For each one of them, you can draw a right angled triangle like that
Do you know what the side lengths are of that triangle?
Say if a point (x,y) is on that circle, what can you say about x, y, and r?
3 4 and 5?
No
Where did that come from?
If r = 5, then the point (3,4) would be on the circle, and the triangle could be a 3 4 5 triangle
But that top right vertex could be any point on the circle
i refrenced this a while ago
Here are another couple for clarity
Yeah so 3 4 5 is just one possible right angled triangle
It's "common" because they're low numbers, and 3^2 + 4^2 = 5^2
But mathematically it's not anything special
alright
Does that make sense?
Okay
Can you work out what the base and height lengths of that triangle are?
Given that the middle of the graph is (0,0) and the top right corner is (x,y)
Your choice
yeah i gotta sleep
You're 1 conceptual leap away from getting the whole thing
But yeah come back to it in the morning
alright thanks
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Can someone please help me on this question
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Still stuck?
i moved on to a diff q
Alr
Btw this was a one liner ._.
Look up Menelaus lol
No need to beat yourself up
$\frac{BE}{ET}\cdot \frac{TA}{AD}\cdot \frac{DC}{CB} = 1$
Arya
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Hi im having trouble with this math question for geometry, were doing trig and im stuck on where to go from here.
,rccw
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3
Label the vertices in this figure and repost
Where's the labelling?
@storm widget Has your question been resolved?
I lied i did it
!done
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i am not sure where to start here
Area of a ||gm = 2wice the area of either triangle cut by the diagonal
oh
^^
You know how to find area for ABC right? 0.5 |a x b| ?
is this linear algebra?
calc 3
i was gonna say, is it possible to use determinant
you can also find diagonals d1 and d2 and do d1 x d2 /2
why ping?
oh if thats the area than this should be simple ig
my bad idk that setting turns on all the time
ok ill try it then
btw the a and b are side vectors AB, AC or AB, BC, any of those
Alr
oh wait so the area of the parallelagram is |a x b|
|AB x AC| to be precise
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Lol XD
that one looks like what i thought the other one was
3d
:<
i guess i should find 3 vectors first?
This calculus 3 video tutorial explains how to calculate the volume of a parallelpiped using the triple scalar product formula.
3D Coordinate System: https://www.youtube.com/watch?v=EzJP9uwV3ms
3D Distance Formula:
https://www.youtube.com/watch?v=0c6cP2zLC2c
Equation of a 3D Sphere: ...
there, that'd add to your set of 3D visualization skills :p
great, thanks!
ooooh
i dont even have to watch the video to understand what's going on here
did it!
tysm @past widget and gn
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Theorem 2
Let Dom(Circle m k) denote the number of ways to place
k indistinguishable and non -overlapping dominos on a circular sequence
of numbers 1 ,2,...,m, where each domino covers two numbers Then,
Dom(Circle m, $k)=\frac {m}{m-k}(\begin{matrix} m-k\ k\end{matrix} )$
Proof:
The strategy adopted here in enumerating the number of place-
ments works by counting the number of placements in classes of placements
which are both disjoint and exhaustive.The total number of placements is
therefore be the sum of the number of placements calculated over the entire
set of these disjoint (and exhaustive)classes.
Consider the following two classes of placements:
(i) the class of place-
ments where the number 1 is covered by a domino and
(ii)the class of
placements where the number 1 is not covered by a domino.
These two
classes are disjoint and exhaustive and we use them here to evaluate Dom
(Circle m. $k$
The number of placements in which m and 1 are covered by a single
domino (as shown above) is clearly given by Dom $(Linem-2,k-1)$ . By
the same token.the number of placements in which 1 and 2 are covered
by a single domino is Dom(Line $m-2,k-1)$ The number of placements
in which 1 is not covered by any domino is clearly given by Dom(Line
$m-1,k)$ Summing the number of placements in the two classes gives:
$Dom(Circlem,k)=2Dom(Linem-2,k-1)+Dom(Linem-1,k)$
$
=2(\begin{matrix} m-k-1\ k-1\end{matrix} )+(\begin{matrix} m-k-1\ k\end{matrix} )$
$
=\frac {2(m-k-1)!}{(m-k-1-(k-1))!(k-1)!}+\frac {(m-k-1)!}{(m-2k-1)!k!}$
$=\frac {(m-k)!}{(m-2k)!k!}(\frac {2k}{m-k}+\frac {m-2k}{m-k})$
$=\frac {(m-k)!}{(m-2k)!k!}\cdot \frac {m}{m-k}=\frac {m}{m-k}(\begin{matrix} m-k\ k\end{matrix} )$
my alternative method
let 1 be number not covered by domino,
let 2 replace the number covered by domino,
circular permutation=(m-k-1)!,
repeated 2 = k!,
repeated 1= (m-2k)!,
final answer is
(m-k-1)!/(k!(m-2k)!)
my logical answer is missing multiplication by m to be correct what logic did I miss
Alex
Does your method only count the cases specific for (1, 2) in a circular setting? Cause then counting the same for {(1, 2), (2, 3), ..., (m - 1, m), (m , 1)} gives you m times this count [cause for each setting one number does not have a domino covering it so each cases are disjoint]
did not understand sir
@dense linden Has your question been resolved?
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<@&286206848099549185>
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hello i’m confused on how to do this
all i know is it’s probably either B or D?
because it should:
have one y value correspond to one x value
must fail horizontal line test somewhere
but how do i know if it’s B or d?
When you look at D
Can you find in (-oo, 0) two x values with the same same output?
Ok maybe even easier, does the function in D pass the horizontal line test in (-oo, 0)?
No
it doesn’t
So that makes the function in D not one-to-one in (-oo, 0)
ohhhhh
leaving you with only one option
and for B it does pass it
yes
so answer D
no
which one
which one
the answer
what is the answer?
B?
See there is a difference
when you consider the function in B on a specific interval like (-oo, 0)
then it actually passes the horizontal line test
cover the right half with your hand and see
but on the whole interval (-oo, oo) it fails the test, yes and which it is supposed to
ohhhhhhh
so on (-oo, oo) it is not one-to-one which you want, but (-oo, 0) it is
that is the criteria you were looking for
i see i see i see
thank u sm
i’ll pay attention to the intervals
in further questions
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Hi, I don't know what question 22 means about "gained a mark. could someone help me out
it translates to "how many students had scores b/w 43 and 64"
43 is one standard deviation below the mean
and 64 is two standard deviations above the mean
you'd use this
between
yeah
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I have no idea how to solve it. Can I get help?
@naive otter Don’t I start with geometric series expansion?
You first integrate
To get an easy function
it will be of the form kln(1+x^n)
And you already know the expansion of ln(1+x) so you can expand it !
you can use geometric series expansion alternatively as you said
start with 1/(1-r), let r=-x^3
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is ln(2)*(1/2)+3/2 the correct answer?
please send your working
!show
Show your work, and if possible, explain where you are stuck.
I’m getting something like -1/2 -1/2ln(1/2) not sure though I don’t have paper or a pen
no way!
Cosx = t and integral of Lnx right
$\int_{\frac12}^1 \ln(u)du$, right?
;(
or am i tripping
u=ln(cosx)
du=(1/cosx)(-sinx)dx
v=-cosx
dv=sinxdx
ln(cosx)(-cosx)-∫-cosx*(1/cosx)(-sinx)dx
=ln(cosx)-cosx-∫sinxdx
=ln(cosx)-cosx-(-cosx)
=-ln(cosx)cosx+cosx
my brudda in christ
now we just plug in pi/3 and 0
why did you not do u-sub first 😭
uh yeah...
but this is better imo...
-ln(cosπ/3)(cosπ/3)+(cosπ/3)-ln(cos0)cos0+cos0
=-ln(1/2)(1/2)+(1/2)-ln11+1
=-ln(2^-1)(1/2)+3/2
=-(-ln(2))(1/2)+3/2
=ln(2)(1/2)+3/2
so how u do this
;(
yeah ur answer isn't correct
why
let me see
did u see it
no
oh
😔
so are u going to see it?
i can't find it
it must be somwhere in between plugging in and the derivation
oh i see now
is the integration done correctly?
can you please tell me where exactly and what i did wrong please
$-\ln(\cos(\frac{\pi}{3}))\cos(\frac{\pi}{3})+\cos(\frac{\pi}{3})-(-\ln(\cos(0))\cos(0)+\cos(0))$
;(
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Someone please help these series make my brain explode
$S_n-S_{n-1}=a_n$
;(
oooh ye
$\sum_{n=1}^{\infty} a_n=\lim_{n\to\infty}S_n$
;(
Sn= a1+a2+a3+...+an-1+an
Sn-1= a1+a2+a3+...+an-1 right?
thats how u get it
yep
and sn is also sommation n=1 infinite an?
just for notation
i know the steps now tho
yes
👍
great thank you
well, $S_n=\sum_{k=1}^n a_k$
;(
you don't know whether the last term is 1 or -1
therefore you cannot do that grouping
QED
there is no last term

we define it by the limit of partial sums
but if you change parentheses, you change the partial sums, so you also change the limit
try a_n = n and b_n = -n
Sommation of 0 is 0 aaah
1, 2, 3, 4, 5...
-1, -2, -3, -4, -5...
i want to go back to just normal limits
you can't necessarily conclude, because of the nature of sequences
and i hated normal limits already
nope
alright that was it for now probably get back here in like 10 minutes
thank you guys
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for m>=2 is this even defined?
Please don't occupy multiple help channels.
the binomial coefficient is just zero if the bottom number is bigger than the top number
@fair forge Has your question been resolved?
and (0.5 choose n) ?
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Im not sure how to evaluate this
no im not sure what you mean
You need to make a substitution and change the variable you are integrating with respects to, so in this case you'd do u=2-5x => du/dx = -5
If you don't know about this method I'd recommend looking it up on youtube or the internet, just search "u-substitution"
Strange, this problem looks like it was made to teach you that method. What class are you in?
this is supposed to teach "indefinite linear composition"
i can do this same problem without the 8 exponent
thats the problem
i would just do the natural log of |2-5x| times -1/5
thats what i tried and it doesnt work
if you absolutely have to use the u substitution then idk maybe its not disallowed
I never heard of this method before and just looked it up, it essentially achieves the same thing as u-substitution it's just less powerful
I think you did it correctly give me one moment to check
i just looked and the next topic is about u substitution so i guess they are just trying to teach us multiple ways even if one is really better
i know how to get the integral of (2-5x)^8 and i can get the whole fraction without the exponent but together im not sure how to make it work
This indefinite linear composition method seems seems kinda stupid to me. I wouldn't put much time into it if you're learning u sub next topic.
After integrating I got -24/35 * (2-5x)^(-7) + C
You need to use the power rule when you have an exponent
This one but backwards
Whenever you need to integrate something of the form x^n where n is a constant
It works the same way when it's at the bottom
It just becomes negative
If you know your exponent rules
yay
idk how i didnt see that thank you
you're welcome, good luck
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how do i find the second part
pythagoras??
noo
cosine rule
ngl i dont understand this
Nyxzore
what values do put for each letter
so c is the side opposite to the angle you want and a and b are adjacent
its basically the big brother of pythagoras
yep but works for all trirangles
thbut this is like a pyramind on top of a cubiod
for my ai i got 20.67890835
was this correct?
so 20.... is the length of ai?
the number above mb
you use pythag for that?
ye
ummm mr Nagi
ye?
thats what i just got for length of AI
20.67890835
💀
,w sqrt(4^2 + 7^2)/2
,w sqrt(19^2 + 4.03112887414^2)
okay mr nagi im pretty sure thats ai lenth
ight thx
werent you asking about the angle...
cooncur?
$15^2 = 19.422922^2 + EI^2 = EI(19.422922)cosx$
Nyxzore
,w sqrt((sqrt(4^2 + 7^2)/2)^2 + 4^2)
did you get that for EI?
,w arccos((15^2 - (19.422922^2 + 5.678908^2))/((5.678908)(19.422922)))
,w arccos((15^2 - (19.422922^2 + 5.678908^2))/(-(5.678908)(19.422922))) in degrees
bro lemme just grab a calculator woldram is tiring
kk
$15^2 = 19.4^2 + 5.7^2 - 2(19.4)(5.7)cosx$
Nyxzore
should i put it into the thing?
i coulndt do the anlge
it was 33.2 for the angle
the line one was correct
but we gotta redo cus the pass mark is 95% and 4makrs would cost me too much
i hate the question reset tho
😭
ima send all 3 wich one do you think is easiest
is this a test then?
nah homework
put our tracher is realy strict cus we top set matsh
ima just put if on the chat thingy again
respond if you have enought time
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how do i solve this iwthout useing euler's form
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Differential equations: Possibly stupid question, I'm able to solve the integral as arctanx but unsure what to do with the 0 and y limits
like will it literally just be arctan(y) - arctan (0)
oh ok i was way overthinking thank you so much
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If $x=\tan t$, and say $x_{\text{lower}}$ is the lower bound, then the relation is just $x_{\text{lower}}=\tan (t_{\text{lower}})$. Same idea with upper bound.
SWR
Oh wait lemme look to make sure I get it
OHH yep that's what I was forgetting yep thanks so much
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✅
@kindred pier sorry for the tag, just want to clarify -- so then lower limit is still 0 but upper limit is tan(y). Evaluating integral gives arctan(tan(y)), is this a normal form of answer?
Like normally something like that would set off alarm bells but is that to be expected for diff eq
$x_{\text{upper}}$ is the upper bound of your integral with respect to $x$. If you change your integrating variable to $t$, then your new upper bound must be $t_{\text{upper}}$. You can use $x_{\text{upper}}=\tan(t_{\text{upper}})$ to find
$$t_{\text{upper}}=\arctan(x_{\text{upper}})=\arctan y$$
So, $\arctan y$ would be the upper bound of your integral when it is with respect to $t$.
SWR
Ahh yeah I was just doing tan(xupper) instead of tan(xlower)
So then that leaves me with arctan(arctan(y))
as the evaluated integral
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Let’s say, I get €15,97 of interest rates on my savings account on that month. The interest rate is 7,90% in a year scale, and the money is given out every month.
The tax is 22% so minus €3,52.
And I get €12,45 in total.
Now. How much do I get realistically if we count the inflation? The inflation now is 4,8%.
Please don't occupy multiple help channels.
@high hawk, please stop spamming channels. I get that you've been trying to get help for a while now, but if no one is helping, it's probably because not many helpers here deal with finance questions
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btw it's really interesting you got to 12.45 monthly earning after adjusting the taxes and the interest. did you perhaps try adjusting for inflation and still not match the answer?
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z1 = 1 - i, z2 = 4i
calculate |z1 + z1 * z2|
I don't understand what happened in the first step, that is, from |z1 + z1 * z2| --> |z1 * (1 + z2)|
its just factored, lol
$a+ab=a(1+b)$
;(
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👍
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x^2 - 8x + (8/2^2) + 5 = (8/2^2)
(x + (8/2))^2 + 5 = (8/2^2)
(x + (8/2))^2 = (8/2)^2 - 5
x + 8/2 = 8/2 - sqrt5
x = 8/2 + 8/2 - sqrt5
x = 8 - 2.23
x = 5.78 OR 5.8 rounded```
- Where is the error?
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Ah
do you know?
Let me read
So -2ab = -8 implies that a = 1 and b = 4 right ?
Seems fine?
Why not adding +16 so that its b²
You wrote 8/2²
Oh wait maybe I did not read closely
you need to pull that ^2 out of the brackets
(8/2)^2
(8/2)^2
In that case yes
so i did not make an error?
Which is 4 also
Parentheses written wrong
but the answer, was that correct?
how is 5.8 wrong
but i think i still considered that as having it
which line?
Just telling
Seems like a sign error has to be in there somewhere
Expand (x+8/2)^2
You won't end up with a minus sign
Before before last line its - not +
you need to be more precise in your writing
(x+(8/2))^2=(8/2)^2-5
x+8/2=sqrt((8/2)^2-5)
bc this answer means its rather lower than 4 or greater than 7

