#help-23
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wdym
you can use the sin^-1/cos^-1/tan^-1 function on your calculator to find the angle
BFC yes
Ohh
Sorry, I didn't read the question well enough
Thanks for clarifying
This was embarrassing xD
Thanks a lot
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Log n! = log 1 +... + log n ~ integrate (1, n) log x dx
can someone briefly explain this to me?
yep
ok, now we'd like to get a rough idea of what that is equal to
and essentially, we're taking a sum of values of the logarithm function
we don't have a great way to know exactly what its equal to without just calculating
but we using the trick of integration to find an approximation
so usually we think of integration as summing up thinner and thinner rectangles under the curve of the function we want to integrate
right
and so to approximate the integral, one might use rectangles of a certain width
say 0.25
okay
so if I want to integrate a function f from 1 to 2, I'd say it's about f(1)*0.25 + f(1.25)*0.25 + f(1.5)*0.25 + f(1.75)*0.25
have you seen this type of stuff before?
not quite but i think i roughly follow
if your step is of size i, then the area of the k-th rectangle under the curve is f(a + ki)*i where a is the start of the interval
f(a+ki) is the value of the function at the start of the rectangle, and i is the width
so by multiplying them you get the area of that rectangle
is that clear?
one sec im trying to sum up what uve been saying to see whether im understanding u properly
I might be explaining it very badly but its the basic idea of integration, sum up lots of rectangles under the curve and the step size i tends to 0 to give you the value of the integral
okay so to sum up wat ur tryna say:
we are trying to find log(n!), aka finding the sum of values of the logarithm function
integration is a bunch of rectangles below a curve, so now were using this tactic to find the approximated value of log(n!)
we expand it to log1 + log2 + log3 + ...
so the rectangles under the graph would be like f(1) * a + f(2) * a + ..., where a is the area of a rectangle under the graph
yes
I should have been more clear, I'm doing a bit of the detour with the integration stuff
what I'm trying to get at is that usually, you use rectangles to approximate an integral
right
but in our case here, we will be doing the exact opposite, we'll be using the integral which we know the value of (since we know the integral of log x) and we'll notice that our log(n!) is actually summing up rectangles in such a way as to sort of approximate that integral
or this
because notice that you're summing up values of logarithm with a step size of 1, each time you evaluate it 1 further
yeah
so log 1 + log 2 + log 3 + ....
that's like setting i = 1
the width is 1 and the step size is 1
so whatever it is equal to should be somewhat close to the integral of log x, since its an approximation of log x
i dont quite get the i = 1
sorry, but do u mind drawing it out lol
i think itll be easier to understand on a graph
I can try, yeah
tysm
not sure how I'll send it
hmm
I'll take a picture
sorry its taking a while
umm
there's a command
,rotate 90
aye
there ya go
lemem take a look
so the integral of log x is the area under the curve
and I drew these boxes here that seem to, if I were to sum up their area, be about equal to the area under the curve
and how do I calculate their area? well their width is always 1, and their height is just the value of log at the start of the box
so for the k-th box, it's log(k)
so we sum up their area by doing the sum of log(k) for k going from 1 to n
how did u know that their width is always 1
is it just something that we decided on
so you agree that the area of all those boxes combined is our log 1 + log 2 + log 3 + ... ?
yepp
ok, but now if we know the value of the integral, we get an approximation for that sum right?
since they roughly represent the same area
wait one momenet
so now i understood this: log n! = log 1 + log2 + ... logn
and that this is just the area under curve
for logn!
not quite no
log n! is just a number, its not a function
so log n! has no curve
instead, we know that log n! is exactly equal to the area of all the boxes I drew
ah so its a number that represents the approximated area under curve
yes
under the log curve consisting of log1 + ... logn
okay
so now we are trying to find the approximation for it
which can be represented in
log n! ~= n log n or (the pic)
sterling's approximation is actually quite hard to get to
ohh i see
its a worse approximation, but much easier to establish
so how do we get to it o.o
so logn! is the exact area of all the boxes combined
but the area of all the boxes combined is an approximation for the exact area under the curve of log x
therefore, log n! is an approximation for the exact area under the curve of log x
right
but that goes both ways, the exact area under the curve of log x is an approximation for log n!
right
so now we just need to calculate that exact area, and we get our approximation for log n!
and how do we calculate the exact area under the curve of log x?
its not by integration right? since we established that integration is an approximation
integration is not an approximation
if you integrate the function, you get the exact area under the curve
I might have confused you with my previous things
the integral itself is exact
oh but the one we did is that we made the "boxes" larger and made the height log x
so the one we did is an approximation
yeah
yep
to get the exact value
of the area, yeah
there is a little detail that might be easy to miss, but its about the interval on which we integrate log x
wait i still dont quite see how we can get nlogn, sorry
i get everything weve discussed but not nlogn
we'll get to it
so notice on my little drawing firstly that the very first box is actually just a line with no height, since log 1 = 0
right
but also that if you count only the first box, then in theory you get an approximation of the area under the curve of log x between 1 and 2
yeah that's why I say in theory, obviously its a bad approximation but I'm making a point about the interval of integration
ah i see
if I take the first 2 boxes, they go from 1 to 3, first box goes from 1 to 2 then second from 2 to 3
so if I take n boxes, I'm actually approximating the integral of log x from 1 to n + 1 instead of from 1 to n as you might expect initially
right
so we get log n! ~= integral log x dx from 1 to n+1
right
have you ever integrated the log function?
ok, so there's a little trick
you can do it by parts, if you take one of the parts to be u = 1
log x = 1 * log x
it sort of comes out of nowhere but this is an integral that is just good to know
you can work it out yourself if you want, or you can just believe me that you get x*log x - x as the answer
you can check by differentiating that, it gives you log x + 1 - 1 = log x
x*logx -x is after integrating logx right?
yep
right
and since this integral has bounds, you just evaluate it at those bounds
right
okay wait so
log(n!) can be expressed as log1 + ... logn
then in the rectangles drawn
the first rectangle has height 0 so the area under curve is 0 which is theoretically right
then since to find exact area under curve for logn from range 1 ... n + 1, we integrate log(n!)
and we will get x *logx - x
then we have to sub the 1 and n + 1 inside
these are the "bounds"
then im assuming after this we would get xlogx?
integrate the log function, not log(n!), but yes
ah right
is this right?
well we can check
thing is, isnt this the exact value under curve
wait no
its because of the 0 - 1 rectangle
so its inaccurate but approximately accurate
i think
ahhh i see
all the rectangles have a small mistake
the tiny gaps between all recntagles and the curve?
no problem
when did u learn this
I kind of learned it several times
but in discrete maths I did an exercise which made me kind of figure it out by myself
but I had seen very similar things before
ah i see..
do u mind if i ask u these types of qns in the future lol
cus ur explanation is really clear compared to alot of other people here ngl
but if u dont want me disturbing its fine haha
I might not be available super often, but I don't mind the idea
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Hey guys I've got a question. Was anyone in grade 10/ year 11 and planning to go to the ib or ap track? If anyone is now in thd ib or ap track can you tell me the topics you guys studied in that year 11 / grade 10 not only for math but other subjects please? Thank you.
Ohhh alright thanks tho. Tho do u have any advice that could be helpful for me this year?
what year are you in, and what are your classes right now
I'm turning year 11/ grade 10 my classes r math physics bio chem English drama moral education history i think that's pretty much it the rest is related to languages of my homecountry and stuff
Tho this year I will be taking calculus and that other stuff
@lucid tartan Has your question been resolved?
pretty good classes
I would just say organize yourself and dont fall behind on anything
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is this correct?
4x4 matrix
would you be able to explain
@smoky aspen Has your question been resolved?
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I’m trying to do this with polar coordinates up top. Where am I going wrong? Is it wrong for me to cancel the derivative with the integral there somehow?
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<@&268886789983436800>
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Hello guys,
I have to learn about implication at the moment. I have a problem with the third case and hope someone can finally clear it out for me.
Let's say p->q.
Why is it that if p is wrong and q true the whole statement is true?
If I say it's raining is p and q the street is wet, the statement says its not raining but the street is wet. Why is this statement true if the forth statement says when its not raining the street is not wet. Doesn't the third and forth statement contradict themselfs?
And how can the street be wet when it's not raining?
I understand that the original statement when it's raining the street is wet does not have any relation with the third and fourth case cause the p is not fulfilled. But why do mathematicians still say that the third and fourth case are still true although we can't verify any of our original statement with it.
Isn't it better to write a question mark there cause we can't tell?
In mathematics and logic, a vacuous truth is a conditional or universal statement (a universal statement that can be converted to a conditional statement) that is true because the antecedent cannot be satisfied. For example, the statement "all cell phones in the room are turned off" will be true when no cell phones are in the room. In this case,...
@supple coral p -> q means that 'p implies q'. Which, translated, means that if p is true then q must be true. If p is not true, the statement says nothing about q. q might be false, it might be true. Therefore, the whole statement is true because p was not true -- therefore the statement isn't wrong
So you guys say that because we can't prove our statement in those cases we can't say it's wrong and therefor have to say it's true?
But doesn't that implication in logic bring a lot of problems with it?
If any of those cases in logic is used, it is not the truth, but it is the vacuous truth, which means it can't be proven. If it can't be proven logic that uses those cases is unusable in a practical matter?
@clr @hsp
no
you could technically assign other truth values to such statements, but they would make a lot of dealing with it very inconvenient (you'd have to special case a lot of things in general statements)
for example, one pretty intuitive notion is that if something is true for all members of set B, then it's true for all members of set A if A is a subset of B
what if A is the empty set?
are you going to have to qualify "except the empty set" after each time you say that?
people choose to define p->q as "not p or q" because it makes everything much easier
we want things like q -> q to be intuitively true without considering the truth value of q
if you make the comment that "p -> q" should be false or indeterminate when p is false, then suddenly you have a whole lot of inconvenience
another example deals with the laws of arithmetic: maybe we like to formalize the fact that if x = y, then x + 1 = y + 1, perhaps as an implication (x = y) -> (x+1 = y+1). Under schemes where you don't accept vacuous truth, then are you going to say that the implication based on the laws of arithmetic is invalid or semi-valid when I say something like 0 = 1 and derive 1 = 2 from that?
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Find all f:R->R that satisfies
I'm pretty much stuck on this, I tried plugging in a few numbers but I couldn't find anything useful
Can someone give me an idea on where to start on this?
@lean otter Has your question been resolved?
Not sure what the final answer will be, but definitely useful to plug in x=0.
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x2+y2= 25
how do I isolate Y
I'm literally a 4.0 student, I just saved math for the last year of my degree because it gives me nightmares
whatever I don't have to defend myself
help
well I need to figure out if this is a function. the prof says to isolate Y
x²+y²=25
y²=25-x²
y=+-√(25-x²)
okay so not a function because of the square root
oh shit someonese channel mb
what do you mean by "not a function because of the square root"?
@flint nest Has your question been resolved?
Here's what I mean, y = √(x) is still a function, even with the square root
As a rule of thumb, when y is raised to something even, it's usually not a function
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f
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What does z sub k mean?
@vital dirge Has your question been resolved?
@vital dirge there is not one n'th root but n
in this video they are named z_1, z_2, ..., z_n
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why when I move a function y=kx+b left horizontally for a units, the the function will be y=k(x+a)+b and not y=k(x-a)+b
Think about it graphically
you're moving it to the left
Instead of thinking of it as moving your function to the left by an amount a, think of it as moving your graph to the right by an amount a
so you're moving it a negative amount
so say you move it 4 units left
then it would be y=k(x-(-4))+b
how can it benefit me in anyways
I still don't get it
It's how that works...
just think of it as a graph going up and down, if you add, the graph goes up and the function will look like it shifts to the left
It's the same thing seen in different ways
It's just to understand where the seemingly wrong sign comes from
Think of a line y=x
y is 1 when x is 1 right
But if you give the x side a bonus one.
y=x+1
Then you can get the y value of 1 while x is zero
it'll look like it shifted to the left when in fact, it was moved up (+) and vice versa
Plus one to x, is like saying x needs one less to get the same y value
i always learned it like inside is opposite, outside is the same
wait wait I get it now thanks
so if it's inside parenthesis then you change the signs
and if it's outside then it stays the same
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Hi, I am stuck here in the "explain your reasoning" part I have done the calculations and have gotten K = 0,1 but I do not know how to explain the reasoning
Exactly
You need to calculate the limits for x->0 for RHL and LHL
And then equate the two and find K
The reasoning is as @thin token mentioned
yea basically write it in a full sentence form
That's the definition of a continuous function at a point
yes exactly
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Find the probability of picking 3 vowels and 2 consonants when 5 letters are picked (without replacement) from a set of alphabet tiles
So far I have 5/26 *4/25 * 3/24 for the probability of the vowels
But I think that might be off
No
Are you familiar with factorials
Yeah
What class is this may I ask?
Algebra 2
Gotcha
So I’m learning P(ab)=P(a)*P(b following a )
For dependent probability
Or
P(ab)=P(a)*P(b)
For independent probability
Does that make sense
So you are familiar with nCr?
Yep
Cool
So the total ways of choosing 5 letters from the alphabet is 26C5
Do you understand why?
Ohhh that makes sense
Yeah
Except since every time you take the letter out and it stays out, do both numbers just drop one??
Ok
That calculation will be as follows: There are 26C5 choices for you to choose a 5 letter word. The choices to choose 3 vowels are 5C3
And the choices to select the 2 consonants are 21C2
So the total number of ways of selecting a word with 3 vowels and 2 consonants is 5C3 × 21C2
So 2100?
Now to get the probability you need to divide this by 26C5, the total ways
Yes
Or 105/3289
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✅
How would you do this if you replace the letter
So you always have all 26 letters each time
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idk how to do
initial velocity is when t=0
acceleration is rate of change of v so differentiate v wrt t
when u get an expression for acceleration, solve for when it equals to zero
the last one u can take the time obtained in part c and sub it in to get max velocity
@little sorrel Has your question been resolved?
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Need help
,rotate
@sand condor Has your question been resolved?
<@&286206848099549185>
@sand condor Has your question been resolved?
(a^n)^m is the first question, let's tackle this step by step
And also
You've nearly solved the problem\
Easy that’s a^nm
LCM
Exactly
Now
Do the same with
(2^1/3)^1/2
Dont we need same numerator
Nearest is 6
Again, first, what's this (2^1/3)^1/2?
Like you've said before
With the a^mn example
1*.5 = 0.5
The fractional form, please
Huh?
(2^1/3)^1/2 = 2^(1/3 * 1/2)
Got it until here?
It's 2 raised to 1/2, remember?
How did you arrive at 5/6?
Cus we need same numerator
Have you learnt how to multiply two fractions? Could you help me out with a/b * d/c
Ad/bc
1/6
Ok
Because we have Base 2
Yes
Because we have the base = 2 in both the terms
What happens when we multiply them?
What is a^b x a^c
A^b+c
My answers are giving me diffrent
Did you the calculations right until here?
Ours is wrong
Why is ours wrong
Wait...
You got it?
Yes
What was it
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I don’t understand how they got the second step
Factor out 1/2 first
now you are only integrating
$2\int{u^{-3}}$
wellll
and then you can factor out the 4 as awell
Rαιη
so the 4 and $\frac{1}{2}$ cancels out to get the 2
Rαιη
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a
b?
ahah it's ok, what's the question?
basically im doing some u-substitution but im stuck after getting u and du let me get the question typed up rq and ill walk though what i've done so far
If you don't want to type you can send a photo of your work
well actually its not much work ill just paste a pic of the question and explain what i have
so I have
u = e^2x
du = 2e^2x dx
but now I am confused if I even used the right term to sub cause i believe I could sub everything if I make e^2x u and the composition in the sin du and have 5/2 outside the integral
but i dont know if thats even correct
How about u = 5e^(2x)? That will make stuff easier
So we don't leave that 5 inside the sin
ah word so
u = 5e^2x
du = 10e^2x dx
yeah i just did that and it was 10x easier lol
Did you get it?
Nice, well done
have a great day thanks again
u too
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$\int{4sin^{3}(t)cos(t) dt$
heep
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if i wanna find the intergral i could move the 4 out of the intergral and just do substitution to solve it right?
Yes, 4 multiplied by the integral
bet and if I wanted sin^3(t) to be U the deriative would have to do the chain rule twice for the exponent and the trig function right?
Think of a more simple sub
could i do just sin(t) and have u^3 du?
Hell yeah
word I just get confused with the format of trig functions and exponents lol
also since this is a definite integral so if I have sin^4 (x) I would find the value of sin(x) and take that to the power of 4 right?
Why do you need to do that?
well i didnt show it but its the definite integral from pi/2 and 0
Right so change your bounds according to your usub
And do the integral as you normally would but with u
for sure thanks
should i get into the habit of changing the bounds to my usub because what i typically do is just sub u with the original value so I can use the original bounds
As in, you replace u back with sin(x) at the end and use the original bounds?
You can but you need to be careful in the intermediate steps
Something like this works
$\int_{x=0}^{x=\frac{\pi}{2}}u^3, \dd u$
ΣAC
So people know which bounds are for which variable
ah ok should I do it like that cause I just typically dont write the bounds for the U steps until i change back
If you don't put "variable=bounds" ppl will assume its the bounds for the variable at the end of the integral
bet thanks
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I
Yes
jswatj
1 + 4x
jswatj
and your goal should be to get $4x\rightarrow 12x$ not $1\rightarrow 12x$
jswatj
yes
Wait how come.. this one video I watched he did the leftward digit first
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Hi
Q.28 Is the sketch of the img correct??
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Wtf bruh
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Need help with solving log equations please?
Ok.
hustlers university is good
when u add logs of the same base, u can multiply what is inside aka
log a+log b=log ab
then from there take 6^ left and right side
Is that right?
yep now take 6^ left and right side
6^ is 6 to the power of
alternatively just take the definition of log
eg
log a(b)=c means
a^c=b
which gets u 36
Ohhh wait I’ll fix it, sorry
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Thanks so much @foggy salmon
np
I really appreciate it
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yea seems right
both?
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Hi everyone, quick question: what is the name of the rule/formula to get the 2nd equation?
its just factorization
But wouldn't it be:
Well you can write it that way, but you want to write the whole thing as a product of 2 factors
So you split the 2x as -3x + x
I'm not sure how you get -3x
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I have to prove the circled proposition by induction
Any tips ?
It’s easy when n = 0
assume it is true for when it is k for some k in N
and try to use the statement u got from that to show that that would imply that Pk+1 is true as well
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ok so i got everything in therms of x and i got: x=lny, x= -(lny)/3 and x = ln5 i am having trouble as to where i go from here
here is the graph
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Combination that equals 75? Wdym
@wind mason Has your question been resolved?
it's unclear what you (or they) mean by "combination", but the three numbers of the input always give 58 if you sum them
Input 1,2,3 = 75
The numbers I’ve posted is what I’ve tried
I can’t find the right combo to get to 75
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Hi
they r saying a is kinda x0, x1 is y after x increases some interval, triangle x is the rate of change od y
Also why are we adding a
they r just saying the width of one S is triangle x
a is the left endpoint of the interval [a;b]
That's exactly why they are adding a
Bc it's the left endpoint of the interval [a;b]
sry im doing smt rn
It's ok np
Don't mind do what you are doing
Have a nice day in this time I'll be thinking about it
Ok now I understand the case for x1
x1 is a+delta x bc the right endpoint is x0+ width of the strip
Which is a+delta x
And that's also the case for x2,x3....xn
wait so u kinda figured out ur question i guess?
Bc as we go from x1 to xn ,the width increases from delta x to ndeltax
Yes
I don't surrender to the question
I keep trying till I find a way to solve it
this isn't exactly a question tho lol
I try to think in a different way if I see that the way of thinking I am using is useless here
Yea ik
It's not an exercise or something
It's an idea
But I should understand it to continue reading
Bc if I skip this without understanding this idea I may face problems later on
Anyways tysm for your time and have a nice day
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Where are you stuck?
b) Idk where to start
Think about what it's asking: what are the values of x that make y=5x-x² bigger than y=4?
sorry for the typo y=4, not x=4
2
It's not going to be a single value, but an interval
Try to look at the graph to find your answer. I which interval does the graph of y=5x-x² goes above the graph of y=4?
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<@&268886789983436800>
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Thanks
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I actually have no idea how to go about this question?
i can only guess that 16x^(2)+4x+1 is the answer because they are all perfect squares
or am i suppose to factor every equation before finding the answer?
it says incorrect
4 and 16 are also perfect squares so why isnt that the answer?
perfect square is when you can factorize and have (ax+b)^2
Because (ax+b)^2 = a^2x^2 + 2abx + b^2 when we expand
2abx
Ah yes sorry
so to solve that i need to remember that equation
a^2x^2 + 2abx + c
and see which of the options fit that
Yes
Also, it's $(ax+b)^2 = a^2x^2 + 2abx + b^2$
dldh06
so it factor a perfect square trinomial i just convert it from the second to the first equation above?
(5x+6)^2?
Thanks dldh06 
What you need to do, for each answer choice, because you know it's a perfect square trinomial, you need to square root the a term and c term of each choice, then do 2ab, to find the middle term
So for example, 25x^2 + 60x + 36
What's the square root of a and c?
5 6
So then what's 2ab?
60
Is there multiple answers?
Then ask
my teacher told me to factor a trinomial where a doesnt equal 1
then i have to find 2 numbers whose product is a times c and sum is b
do i apply that here to this equation to factor it
so 900 and 30 times 30
is 900 and 30 plus 30 is 60
i get (5x+6)^2
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Hello, This is messing with me. I don’t know how to start
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Not sure if it is considered maths, but what exactly is the difference between the proposition form (rough translation from my language) and the boolean form in bool algebra?
Let me know if its the wrong place to ask that
Erm hold on, I'll try to get examples
(A) A blue car
(B) Bill Gates is the president of the USA
(C) x * 4 => 25
(D) The nile river is the longest river in the world.
Rough translation of the question is something like:
Which one(s) are a proposition (or aren't), or a boolean form?
its... weird
Generally speaking a proposition can be true or false.
yea, isnt that the same thing for bool?
I don't know what you mean by "boolean form"?
These things might end up depending on your specific definitions for "proposition form" and "boolean form" fwiw.

Wait so
If we check the examples of earlier
x * 4 => 25
that cant be a proposition right?
because we dont know x? / can be both true or false
I'd say it depends on x. Like, if they mean x is a real number then x * 4 => 25 has to have some truth value, we just don't know what it is.
If not then it could mean anything so I'd say it doesn't have a truth value.
Whatever source you're using though should tell you via defns or examples whether they consider statements with variables in then to count as propositions I guess.
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how would i say "if x is smaller than r, y isnt a part of real numbers"
$$x < r \implies y \notin \mathbb R$$
jnmwn
@lean otter
are there other ways?
maybe
can u help me too lenny
just go in a free help channel :)
using what
okay
like what is x,r?
like sqrt(r-x) = y
??
if x is bigger than r its complex
you could say that
you could say either
but one is a statement the other is more of an equation
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Let a, b be positive integers such that b^n+n is a multiple of a^n+n
for all positive integers n. Prove that a=b
is this true?
a = 1, b = 3, n = 1 holds...
i mean to say 3^1 + 1 is a multiple of 1^1 + 1, but clearly a ≠ b
@muted imp Has your question been resolved?
but it's not a multiple for every n. take n=2 and 3^2+2=11 is not a multiple of 1^2+2=3
🤦 of course mb
I found this on the stackexchange, I just don't quite understand it
which part of it do you not understand
Yes
not helpful
I mean as you said
Doesn't this demonstrate this is false?
Ah I see
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Why is the ratio test usually used to find the radius of convergence?
Quandale Dingle here. It's because the ratio test tests whether it converges absolutely, and within a certain domain because we have x, if that makes sense
Here
In mathematics, the radius of convergence of a power series is the radius of the largest disk at the center of the series in which the series converges. It is either a non-negative real number or
∞
{\displaystyle \infty }
. When it is positive, the power series converges absolutely and uniformly on com...
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For a linear regression to be a good estimator of the relationship between two variables, it needs to satisfy a few assumptions. One of these is linearity in the relationship. As far as I understand, this assumption can be satisfied even if the relationship is quadratic, like this:
$$y_{i}=\alpha +\beta_{1} x_{i}+\beta_{2} (x_{i}^{2})+\epsilon $$
AlexanderJ
...because the linear model still 'sees' the variables linearly; the independent variables are still all only summing to create the dependent variable, and the model 'doesn't care' whether the x² term is actually "x squared."
(I got this from this StEx answer: https://stats.stackexchange.com/questions/92065/why-is-polynomial-regression-considered-a-special-case-of-multiple-linear-regres)
Another separate assumption is that variables aren't multicolinear. As an example: a video I'm watching is explaining that if the number of car/pedestrian accidents in a neighborhood Y depended on the number of people who live in the neighborhood X₁ and the number of cars that drive through the neighborhood X₂, then this would violate the assumption because X₂ is clearly affected by X₁.
But, if we can have a regression that features both x and x² in it, like the equation I wrote above, and it's a valid linear regression, then why doesn't featuring both x and x² in a regression break the "no multicolinearity" assumption?
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<@&286206848099549185> ? 🙏
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Hello sorry for interrupting but I need help ;-;
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So how do I solve that question, because I need to get the common monomial factor.
I've tried searching how to solve it but end up getting the same answer but without the solution
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e²
thank youu
say .close when you’re finished 👍
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please help me understand this
ik that the I is for the x value and the J is fot the y
but i get different answers when i use sin and cos
i got 28 for sin and 151 for cos
so idk what i did wrong
Post work
its mostly on my calc
but ill put it on paper
you can plug in the values in your calc just to make sure
Do you see anything i did wrong
So I can't see anything wrong, but what I recall from problems like this you need to use tangent for the angle
Well, next thing is, you know it's (-15, 8) meaning it's in the second quadrant, so you need to adjust the value of -28 to be in quad 2, by adding 180 or 360
150 it is
so it would be either 1 or 2
and i would say 1 because x comes before the y coordinate
How would you know if cos comes before the sin?
well the cosine function deals with the x coordinate while the sine function is with the y value and if we were to put that as a ordered pair it would be (x,y)
but idk
that just what i was thinking
Well, you can check that, because you are given 17<cos(151), sin(151)> so you can then do 17cos(151), 17sin(151)
so it would be answer 1?
Did you check it?
lemme see
i have to finish the other problems in the section to check it
but they are all the same just with different numbers
yes!
it was right
i got wrong this question though
ohhh i see what i did wrong
i got 32
but since they were both negative
that menas it should of been on quadrant 3
ok anyways thank you
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