#help-26
1 messages · Page 153 of 1
on the left hand side you get |2| + |-3| + |5|
and on the right you get what you expect
can you construct a similar vector as my sign vector? for C
like @surreal mural said
rbit
would v = (1, 1, ..., 1)?
i’m too used to the real version of this kind of problems, what is |x_i|? like if x_i = x_ir + ix_ic then is |x_i| = x_ir^2+x_ic^2 or |x_i|=|x_ir|+|x_ic|?
$x_1 \cdot v_1 = |x_1|$
rbit
no
you want a quantity such that when multiplied by x_i you get |x_i|
is this to do with the sign function cos im not sure how that works here
so |x_i|/x_i
there’s no sign function in C
forget about sign functions, its pretty straightforward
it was just an example for R
this is x_i*/|x_i|
equivalently
x_i x_i*/|x_i| = |x_i|
as we want
you think so?
yes
no
oh is that a conjugate?
yes
well more or less
just be careful with zero
yeah
right so that gives me another vector to use C-S but how does that go into the inequality with sqrrt(d)???
v = (x_1*/|x_1|, …, x_d*/|x_d|)
whats the norm of v?
well try it
hmmm ok
notice that every coordinate of v has amplitude between 0 and 1
what happens when you sum d numbers between 0 and 1
it’s less than or equal to d
but you need to take care of zero coordinates too as @surreal mural said
I think this will actually equal d, because we need to take the absolute first
yeah indeed
@grand blade Has your question been resolved?
is this it???
i mean i get the x_i cant rly =0 so idk what to do about that
@patent trail @surreal mural ???
right like do i just mention that or am i meant to do something else
just let the corresponding coordinate of v be 1
also need to take conjugates
indeed
and then yeah the part where you evaluate <x, v> could be more elaborate but idk
but you need to use the conjugates in v
so instead of saying v_2 = sqrt(d) its less than or equal to sqrt(d)
to deal with conjugates?
ok
oh no that part is fine already
$\frac{x_i}{\abs{x_i}} = 1$
rbit
this one though is problematic
right cos ig if x_i is negative then its -1 right
rbit
oh yeh actually since im squaring them it wont matter right?
its complex numbers
ummm so how does that affect what i have cos i havent done complex analysis yet so im pre dumb when it comes to complex numbers
shouldn't really affect what you already have, just put the absolute value bars and it will be fine (problem is with numbers like i, where i² = -1)
$\abs{\frac{\bar{x_i}}{\abs{x_i}}} = 1$
rbit
forgot about the conjugate
oh ok then thanks
ummm and btw for the next inequality am i doing the same approach where i wanna create another vector to use C-S ???
oh no in this case I'd go with a similar argument to the first inequality
hmm first of all not sure what is meant by a monotone increasing series in this context
like as in it is only increasing cos ur adding non-negative numbers
maybe not worded correctly but i think the idea is there tho
I'd start by choosing some k, such that $|x_k| = \max_{1 \leq i \leq d} |x_i|$
rbit
but I think from there your idea should be right
but this way its a bit easier to see
yeh ok that makes sense
$|x_k|^2 \leq \sum_{i=1}^d |x_i|^2$
rbit
yep thanks that does seem alot better
but anyways how could this method of working help with the 4 inequality
you can apply the same idea, choose a k and then just write out the inequality after squaring both sides and using a slightly different argument you can show that this also holds
@grand blade Has your question been resolved?
not sure if I can even follow this but I think you overcomplicate it a little
the most important step is to see that $d \cdot |x_k|^2 = \sum_{i=1}^d |x_k|^2$ which I think you did see? And from there showing that $\sum_{i=1}^d |k_i|^2 \leq \sum_{i=1}^d |x_k|^2$ just requires you to think about what it actually means for $|x_k|$ to be the maximum
rbit
well ig that unless all the vectors have the same magnitude it be less than since ur adding the biggest magnitude d times
but doesnt my working still work?
can't really follow it, but if you don't make use of this maximum property somehow then probably not
oh hold on
yeah i think you did everything correctly
well i guess i would go like x_1 + x_2 + ... + x_d <= x_k+x_k +...+x_k???
but if u think its good then imma leave it like that
only thing I would be careful about is when saying $|x_i| \leq \max |x_i|$
rbit
just notation wise
yeh ok but rest is good right?
yeah
ok thanks alot btw can i ask what resources did u use for linear algebra cos my lecture notes r rly superficial and skip alot of steps
just be careful with using the index i for multiple purposes at the same time
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was reading a book but i think its not available in english
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You can use monotone convergence here.
You would have to show that the sequence is (1) bounded (2) monotone.
Once you know it converges, then you can find the value by taking the limit on both sides of the recursive formula they give you and solving for the limit L.
Oh ok hahaha that's fine
So there's some mean value theorem type thing going on in here for sure
yea but how🥲
@strong sable Has your question been resolved?
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How equation for D' formed?
x' = x + x0, same for y, it is just translation
2nd order line
@chrome pulsar Has your question been resolved?
what is that
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Pls define a, b, c, d, and s
sides of the cyclic quadrilateral opposite to the vertex
<@&286206848099549185>
<@&286206848099549185> ?
(1) consider area and Ptolemy
what have you tried so far
did you consider area of the cyclic quadrilateral?
i think area could work
(3) I'm thinking you can relate tan^2(beta/2) to some simpler function by using trigonometric identities
i think the wave mean this or that
as in a^2+c^2 or b^2+d^2
and thx i got the first one
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Need help with the 2nd part
what have you tried
cauchy's condensation criterion reduces it to proving sigma 2^(n/2^n)-1 converges
The term in the sum roughly behaves like 1/√n. So which criteria would be natural to use here?
?
Sorry, I am blind. I read ^(1/2)
oh fair
What after that tho
series expansion
We're not allowed to use that yet
Havent been taught in our course yet
thats kinda the issue with a lot of these, but it makes sense
they're doing everything from scratch to make sure nobody is left behind
ok. would have been useful information from the start
what are you allowed to use, then?
- basic definitions of limits and convergence/divergence
- convergence criteria: comparison test and cauchy condensation test
- some results eg. lim (1+1/n)^n= lim sigma 1/k! = e and some others
@long fog Has your question been resolved?
Sorry, if I make an unqualified suggestion again. This reminds me of my real analysis 1 course, in which we got a similar question. Is there any chance that you have the inequality n^(1/n) <= 1 + 1/(2sqrt(n)) hidden in the script?
*Back then we also had very limited tools and this was basically the only way we were able to solve this.
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✅
yeah i was tryna find smth like n^1/n-1<1/n^p, 0<p<1
Did you show the result limit n goes to infinity n^(1/n) = 1?
@long fog Has your question been resolved?
Did you use an upper bound to show it?
I mean if you had this upper bound that I mentioned, the question would be immediately resolved (or any upper bound that is good enough)
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one of the sat questions i was practicing with
i know that triangle GMN is isosceles and MH+NH is 3520 but idk where to go from there
Since MH and a NH are tangent to the circle, the angles GMH and GNH are both 90°. Which creates 2 right traingles.
wait is that a property
Well a tangent to a circle will always be at a right angle with the radius of said circle
oh wait yes
and then i would split the right angle in half to find the individual lengths right
(I hope I worded that correctly, english isn't my first language, so i apologize if something i say isn't comprehensible)
don't worry it was perfect
ah wait
i think i got it now
2(168)+2(gh)=3856
wait that's wrong i think
i'll try it again
Yeah
It is
I also haven't fully figured out the sollution
Just wanted to chirp in with an insight that I thought you would find helpful
it was helpful
i will try doing it again
im
stupid
@blissful spear it was just pythagorus theorem
1768^2 + 168^2 = (gh)^2
Are HM and HN the same length?
That's what I was trying to prove to myself this whole time
if gm and gn are both equal
then h would be in the middle
i don't know the proof but intuitively that's how it should be
Yeah you're correct
because if h wasn't in the middle, that would mean there was a tangent offset (therefore gm or gn weren't equal)
man
i completely forgot that the tangent of the point of a circle and the radius form a right angle
thank you so much though
No problem
@trail sphinx you should close the channel
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can i hab some help with diso
factorize the top
turn the bottom into 1-cos^2
then factorize that and cancel factors
(this is all for LHS)
use difference of perfect squares on denominator
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How do i determine the magnitude of a gradient vector?
For example [7,21,-14] ?
Have you learned about norms
$\sqrt{7^2 + 21^2+(-14)^2}$
Merineth
Would this be correct?
dunno what a gradient vector is, but that is the formula for the magnitude of a vector
agree ^
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Can someone explain part a and how dm/dt=2-.001m
I get that rate out is 2 l/t*m/200=m/100 or .001m
I don’t get have rate in is 2
Is it 2 because 1g of S/L hence as I have 2 l in the fore I have 2 grams of salt coming in
Giving me dm/dt=2-.001m
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how i do dis
Damn
Have you compound it?
whats compound
wut
yes it is
a = sqrt(28^2+45^2)
Correct
and then cos28/whatever that is x cos(pit/6 yada yada
….
...
What’s yada?
u get the point!
but then how can we make an equation for theta
Notice angle compound formula
Definitely not
28/53 and 45/53 are the results yield from trig function
what trig function
Sine and cosine
👆
Correct
Then you should put theta instead of those figures
why
Why not?
yeah
they didnt put theta there tho
You should put theta in the parentheses of sine or cosine
but they didnt put it in their parentheses 😢
Are you referring to this?
yere
oh
You should put trig(theta) or number
ok so if the number is not one on unit circle we put thet?
Not trig(number)
wdym
They define it
The coefficient before sine and cosine stands for two side respectively
Are you deciding to transform it into cosine or sine?
why cant i use tan inverse
……
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Sounds like an engineering class seat arrangement
Show your work
bro
so 8 seats so i would put 1 boy and 1 girl right away at first and last seat and then i have 4 girls and 2 boys left so ill add them and then it would be like
1 × 6 × 5 × 4 × 3 × 2 × 1 × 1
yes idk how pls help
select 1 boy from 3 boys
only 3 boys
and 1 girl for 5
5C1 * 3C1 * 6!
oh yes the combination but we are rwquired to use fcp
and i really dont know how
like idk how to solve it using fcp
FCP?
What is fcp
Yea u can do it with that too
3 × 6 × 5 × 4 × 3 × 2 × 1 × 5
3 boys can seat so 3
and any of 5 girls can seat so 5
Given that all of them are independent cases so we multiply 
same concept like you did for 6 5
uh?
I have mult ;-;
If a boy sits on the seat 1 it doesn't affect the girls positioning on the last seat so the cases are independent
Uh?
wait
why is the last 3 and 5?
and then 6 5 4?
question says first must be boy
and last should be girl
yes
ohhh
and hence we have fixed positions
hey thank u so much
U didn't understand leave it
yes?
u know that fcp can be multiplied or add, how do i distinguish when to multiply or add
adding is generally for cases
can u expound?
yes
pls
if you are choosing outfit with 3 shirts and 2 pants, you multiply cuz each shirt can pair with each of pants
so, 3×2=6
For adding,
if you can take 3 different bus routes or 2 different train routes and for it you add them cuz choosing
one of them wouldn't involve the other
so, 3+2=5
adding is used for mutually exclusive events
whereas multiplication for independent where multiple things can happen at same time
here only 1 event takes place at a time
@shell peak Has your question been resolved?
ohhh so u choose between taking a bus or a train so they are not dependent?
yea, can also connect with real life
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I don't know if this image is very readable, so I linked the pdf. I would appreciate if someone looked at my workings and could tell me where I went wrong. The end result has an extra negative sign which I'm not sure how it got there. I know my workings might not be very clear, so feel very free to ask me to clarify things I've written 😅
Also I'm not sure if the thing I did where I just got rid of the sums on both sides is actually doable. It just felt right I guess?
imtypo asking a question
Fr
Bro is asking bout his working
On deriving the formula for the nth term of the Fibonacci sequence
In terms of golden ratio
Yeah, what's up with that
Right?
Yeah it's the Binet formula
Yea
Let me see bro
Bro
I can't see the pic clearly
I'm on mobile
Pls can u send the pic sir
Separately
Yeah that's why I sent the PDF, since my workings are long vertically, taking a picture that's clear is not really possible. I could take multiple pictures of the different parts if you want
Okok imma try
Here, go left to right, it should be a bit better
Can u pls check the sum
Other side
I mean the right side
Left is correct
@haughty wren
I feel here might be the mistake
There I used the Geometric series formula
Ntg much im just used to you answering questions
,w sum (-a)^k from k=0 to n
Right?
n -> ∞ though
Well yeah but I‘m using geometric series. 1/(1+x) = sum [n=0 to infty] x^n
But I just realized somwthing
What
That only works for |x|<1 and phi is a bit above 1
That's why
I am saying till n
But wait
We do not sum till n to get the nth Fibonacci term?
What?
Don't u think we sum till n?
Nth Fibonacci term is sum of n-1 terms right ?
no
What
Nth Fibonacci term is sum of the last 2 fibonacci terms
$F_n=F_{n-1}+F_{n-2}$
everg
I feel you
All good
F(x) working seems all good
Where is the mistake then
Wait he already realised that
Case for geometric series would not work as |x|<1 but phi is not
Is here where the mistake lies?
I think so. I‘d have to find a way around that
What if we sum to n
Simply n
Can u try that once
Imma too tired do even geometric sum fr
,w sum (-a)^k from k=0 to n
oppa does fr mean "for real"?
Is this correct?
Why I don't feel so
Ya it is
Ok we see for the other one
,w sum (a)^(-k) from k=0 to n
phi^2-phi-1=0
yes it is correct
phi^2=1+phi
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Hello
I need help with this
can someone explain who did we go from eq 4 to eq 5
help 💀
Dam I am being ignored
can you help me out with it
i found $\ v_{tx}=\frac{v , u_x , u}{2a} + \frac{v_x , u^2}{4a} - \frac{v_x , u_x}{2} - \frac{u_{xx} , v}{2}$
Emily
just apply the functions composition rule and the product rule by the book, you should find what i found!
Thank you so much
I'll do that rn
I appericiate you so much
btw, im sure its correct, cuz after that i did
yeah please do share
vxt value is correct right?
can you like solve the entire equation, if it's not too much I am sorry
@paper sage Has your question been resolved?
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can someone help with my thinking for such questions?
would the answer to the first question be n+1?
- because you're not simplifying like terms, you should think that (a+b) appears n times and so there's essentially n holes and in each hole you can put either an a or b
so its 2 options for the first hole
2 for the second
hole?
ok
if n=1
yes
(a+b)
1 term
right
like each summand is one term
yea
ok n=2: (a+b) (a+b) = a^2 + ab + ba + b^2
and when n = 2
how many terms?
4
ok good
ab is one term yea
while a+b is a binomial
for n=2 its 4
for n=3
its uh
a^3 + 3(a^2)b + 3a(b^2) + b^3
oh that's simplified though yeah
yeah don't simplify
think of it like this
there are n choices to make
in each choice
you have 2 options
a or b
either pick a or pick b
yes
so 2 x 2 x... x 2 = 2^n
that's the definition of the exponential right
yess
if you multiply the same number n times
and then for question 2
you get that number to the power n
yeah
for q2 selecting either a or b from each of the n sets of brackets
a) well you have to pick n things, if b is picked r times, then a has to be picked how many times?
that means i would have n number of a's
i have no clue
you have n decisions
b was picked in exactly r of those decisions
so how many decisions remain
n-r ?
yes
TYSM
in how many ways could b be chosen r times from the n sets of brackets?
would that be
n/r
actually it's kinda questionable here if its n choose r or multiply that with r!
I think the latter
b! what?
no
n choose r is n!/(r! (n-r)!)
ah i've never seen that before
in how many ways could bananas be chosen r times from the n sets of brackets
hmm strange they shouldn't be askng you then
yeah
im going ahead cause im not in school for 3 weeks so i need to
that's going to be n!/(n-r)!
be ahead of syllabus
ok
oh
for c) the answer is n!/(r! (n-r)!)
binomial coefficent?
yeah
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i got n = 54, answer key says n = 9?
my step by step was pretty straight forward cause it seems like an easy equation??
(log base 2 of n) - (log base 2 of 1)/(6) = log base 2 of 54
(log base 2 of n) - (0)/(6) = log base 2 of 54
(log base 2 of n) - 0 = log base 2 of 54
(log base 2 of n) = log base 2 of 54
n = 54
i'm just like...
where did they get 9...
divide both sides by 6 or smth??
I am sorry if this doesn't help much, but if n = 54, then the equality wouldn't make any sense since log_2(54) - (log_2(1))/6 = log_2(54) isn't equal
unless (log_2(1))/6 = 0
and it does
wait
yeah i am confused too now
...
log_2(1)=0 because 2 to the 0th power is 1.
nah bro
i'm assuming the answer key is wrong (hopefully)
The answer key seems to be wrong
yeah
Ya
sorry for not helping, you are totally right
You’re all good.
Try taking 2 to the power of each side of this equation for an easier simplification to see what’s going on.
no way that is n = 9
Lol everyone makes mistakes 🙂
this is the 3rd wrong answer on the answer key like ?? bro

whatevs
ty guys
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how can i solve this
the rate of change/slope is (5/-8)
all of these answers have the same slope since both x and y are multiplied by the same value for each one, which when divided by each other equal to 1
what does a unit vector verify?
the magnitude is 1
ahh
i think i see
square both and then see which one is 1?
or sorry, add and then square root?
i forgot how it was done
youd be better off finding the magnitude of -8i+5j
64 + 25 = 89, square root of that
so if you want the magnitude to be 1, what would you do to -8i+5j to get the unit vector in the same direction
add 9i and subtract 4j??
you only want to change the magnitude
v/|v|
uhhh
i dont know?
how can i only change the magnitude without changing the value of a and b
if you multiply/divide a vector by some constant, its magnitude changes by the same factor (the abs value of it)
yeah but then the value of i and j change as well
well yeah, they have to otherwise its just the same vector?
thats what im saying??
i and j are just unit vectors in their own right
so how can i change the vectors magnitude without changing anything else
.
^
its the last option
so what do i need to divide the square root of 89 by to get it equal to one, is that what i should be asking myself?
-_-
you would divide the vector itself by its magnitude
though its been spoiled
i mean i was getting there
thats what i was thinking of since thats the only way to get one in this cases
alr then its seems to be D
think about v = -8i+5j
thanks for your help
yes great
lol
i should write this one down
thanks guys
👍
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Since A * I = A, I multiplied both sides by the inverse of A to get I = 1. If I put all the values of the matrix as 1, would the matrix equal onw?
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Ignore parts a and b
for part c, I got T * T as well
I put T into the calculator and cubed it to get the 3rd year
nvm screw this
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The next question discusses the importance of definability. Let M be the set of names. Prove that M is a finite definition if and only if the following condition holds: there exists a finite series of atomic verses pi1 , . . . , pin and a truth function v:AP→{F,T}, so that all names f :{F,T}n →{F,T}
v ∈ M ⇐⇒ f(v(pi1),v(pi2),...,v(pin)) = T.
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Question about partial fraction decomposition, how would I decompose this?
when the leading power of the numerator is greater than or equal to the leading power of the denominator, you first divide the polynomials until this is no longer true
start by performing polynomial long division, then write it in the form (quotient) + (remainder)/(denominator)
wow ordinary differential equations really does draw from everything ive learned
algebra precalc calc 1 calc 2 linear algebra and some calc iii
Got it, thanks!
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Let ( k ) be any non-zero constant, and the function ( f(x) ) satisfies ( f'' - kf' - f = 0 ) on the interval ([a, b)), and ( f(a) = f(b) = 0 ). The correct statement among the following is:
(A) ( f(x) ) is monotonically decreasing first and then monotonically increasing on ([a, b]).\
(B) ( f(x) ) is monotonically increasing first and then monotonically decreasing on ([a, b]).\
(C) ( f(x) ) is identically zero on ([a, b)).\
(D) ( f(x) ) has exactly one zero within ((a, b)).\
riyobi
@strong sable Has your question been resolved?
@strong sable Has your question been resolved?
Any ideas are welcome!!
hi
are you there
You can try solving the differential equation.
It's constant coefficient. Shouldn't be that hard
It's also homogeneous which makes it even easier
How?
i may lack some knowledge of this
Any keywords?
Auxiliary equation
r^2 - kr - 1 = 0
(r - (k/2) - √(k^2/4 + 1))(r - (k/2) + √(k^2/4 + 1)) = 0
r1 = (k/2) + √(k^2/4 + 1)
r2 = (k/2) - √(k^2/4 + 1)
f(x) = c1e^(r1x) + c2e^(r2x)
This way?
this works
i was checking if there will ever be complex roots but turns out there isn't
you can now calculate c1 and c2 by substituting the boundary conditions
at a and b
that C is true
Why?
why is C true or why does it indicate that C is true ?
it indicates C is true because if it's zero everywhere then it's zero on the given interval
there could be another tricky solution that we don't see
but I honestly don't see it at the top of my head
This is already tricky enough
fun fact that's the standard solution xD
everyone can do that
tricky solutions usually don't follow a standard method
you figure something out just by looking and make a solution out of it
like maybe for example turn this question into a matrix problem and figure out that the matrix is invertible
therefore it has only one solution which is the zero vector
thus leading to C
there could be many ways you can approach this
It's an ode question but it's placed in exercises of single var calculus...
i mean, the world is small, math is all connected
by the way I also just realized the differential equation is only valid on the interval
so it could have any other value outside of it, it doesn't follow the ODE except there
Then what should i do
nothing, the solution still works, because it only asks for the value in the interval
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Hi need a little help with part c, i can't seem to expand it for some reason
In part (c), you're asked to show that the sequence vn = un - l, where l is the solution to the equation l = al + b, is a geometric sequence. By substituting the recurrence relation un + 1 = aun + b into the expression for vn + 1, and using the relationship l = al + b, we find that vn + 1 = avn. This confirms that (vn)n => 0 is indeed a geometric sequence with common ratio a
Also, translate the question, you'll get more help
@lusty lagoon Has your question been resolved?
@lusty lagoon Has your question been resolved?
Sorry I had to go somewhere, thank you so much for your help the answer was right there in plain sight. I really appreciate it
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i need help for my subsusituion grade 10 math work its due in 1 hr and i have a test i just need a bit of gudiance thats all
can we hop on vc
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can som1 help me?Im stuck here and im really confused on how to continue and i think i did most of the calculations wrong .. the result of the expression should be 3a^4b
slay
slay
you have notation issues, inappropriate use of ()
those () i maked with those red x shouldn't be there
you're missing () around the 6a^2 in blue
yes im confused on how to use those🥲
for that component, you should have
ab multiplied to whatever 5a^2 + a^2 simplifies to
i.e. you should have ab * 6a^2 or equivalent
as opposed to the ab + 6a^2 you had
with expressions adjacent to grouping symbols, multiplication is implied
okay
what you had there: $5a^2\red{(\black{+a^2})}$ represents the product of $5a^2$ and $\gray{+}a^2$ which isn't what you want
ℝαμΩℕωⅤ
i think i understand now
try continue from
$$\br{ -\frac 32 a^3b + ab(6a^2)}\br{-\frac 23 a} + 6a^4b$$
ℝαμΩℕωⅤ
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did i do 11 and 13 right?
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I was on Chapter 1 of Calculus by James Stewart and I'm currently doing this question. How do I approach part c?
like how do i find the "least squares regression line"?
least squares is a pretty complicated thing. Are you intended to use computer software for this question? Is that what that green symbol means?
i guess it does
so i just use a software and give the points as inputs
?
hi hayley :waves:
and get the equation?
yea
slayla
water beam
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I'm not too sure what to do with (b)
I don't understand what it means by angle to z-axis
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3 darts are thrown (equal probability of landing anywhere on the dart board). What's the probability that they all land on a same half of the dart board? I am not sure how to start this
Let's take that dart boards is divided in 2 equal part
As we know there is 3 darts there is equal possibility so we can say that 2×2×2 so it will be 8
Let's think that all dart land on 1 st half or 2nd half that means we have 2 possibility so we can do 8/2 which is 1/4 and 25% chance
@eternal pike did it satisfies your answer?
@eternal pike Has your question been resolved?
so for this
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just think abou the total combinations of the dart landing
1st dart has 2 choices where to land
2nd also
and 3rd also
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Result:
2550
@lusty cedar Has your question been resolved?
why is subbing in 4 to the first deravative equal to 3
i get stationary point is three
but still
oh they sub it into the integral
I don't get it though still
oh ffs cause y = f of x
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✅
whats the method for part c here?
So first u can convert tan into sin/cos and then ull get a quadratic in sin
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choose 2 negative numbers and 2 positive numbers from 14 numbers (total 14= 6 positive and 8 negative). multiply those 4 numbers, and we need a positive number. find probability of it being positive
my doubt
if I do (8C2 × 6C2)/14C4 then it gives correct answer
but if I do 8C2/14C2 × 6C2/12C2 then it's wrong answer
can someone tell why is second approach wrong
U mean multiply those 4 numbers?
yes
Why does the other condition exist if we multiply those 2 negative no anyway get a positive no
Multiply those 4 numbers and we need a positive no
its a bigger question, and I'm asking for only one part of it
What's your question?
I'm confused
from 6 positive and 8 negative numbers, 4 numbers are choosen and multiplied. what is probability that resultant is a positive number
I don't need answer for whole question. only the case where we choose 2 negative and 2 positive
other two cases would be all 4 negative, and all 4 positive numbers
<@&286206848099549185>
Ok you can choose two numbers negative no by 6c2 and two positive by 8c2 and now we need to multiply since the cases are independent
6c2 × 8c2
just tell me why this method would be wrong @stuck hearth
This
what's wrong with choosing those numbers one by one
Over counting
In your wrong answer
You count ab cd and cd ab as different combinations
But they’re the same
if i choose 2 negative numbers out of 14 numbers then it is 14C2. then 12 numbers remain. and I choose 2 from it, 12C2
