#help-13
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so what do I plug in for the answers
This is how it would look like
20 degrees, blank, and 1 possible triangle
alright ill try it out thanks
no worries
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Ava
Care to explain where each part comes from?
So, first let's consider how many ways you can choose the colors. There are 5 ways to choose the first and 4 to choose the second, and order does matter here, so that's 5P2 = 5*4.
You have two different colors 4 from 1 and 3 from the other
I might just be misremembering the formula for nPk
Yup
I remembered right
You're selecting 2 of 5 colors
Not dumb, just learning
Next, you choose 4 balls from the first and 3 from the second, but you can choose these in any order as well. 7C4 and 7C3.
But you have to permute these as well, and remove identical permutations, so that's 7C4 * 7C3 * 7!/(4!3!)
Yes
Hold up
You're missing a piece
You can select the 7 balls in any order
Oh nevermind
I don't think you care about order here.
Yes
Then that's the last thing
5P2 vs 5P1
So the last part was just me misinterpreting the prompt
Please disregard
0.36% I assume
Smart
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I need help with this problem. I managed to solve the first part using |W|=K+U
All the kinetic energy would be converted to potential energy so
1/2mv² = mgh
And why is that
Energy cannot be destroyed or created
But can be converted to satisfy law of conversation of energy
Isn't law of conservation of energy
K_1+U_1 =K_2 +U_2 ? Unless I'm making a mistake because this equality is still relatively new to me
The law is initial energy is equal to final energy
In that example we have 4 energy
We can have more or less
In that equation does something go to zero based off the expression your wrote
Idk why the angle is given in the question, maybe I'm wrong
No?
Because my goal is to solve for a distance
And I also remember U=1/2 k(delta s) ^2 for a spring
Oh, then just search up projectile motion
It deals with this
I thought we needed to find how high up the kid went
I already solved the final velocity
Yeah there is a formula to find distance traveled by motion of projectile
Let me find it
Spring to give speed and energy, no?
Is Work a type of energy
Yes
I said when I made this post Work=kinetic energy +potential is that somewhat valid?
I was going to say, can I say work=kinetic-potential now?
To me, it seems like it could work because the unit would still be joules
This what I was thinking. I calculated W from the previous part
Isn't that what u used to calculate vf?
Yes but I used W=K+U
Also isn't x distance of spring compressed or expanded
Ithought we were finding distance of boy
Hm, maybe I'm confusing something
I just think we can find horizontal distance via projectile motion
I would agree with that but the angle is not located near the spring it's somewhere else
Idk how u are getting spring in this
Actually I'm confused
The question is how far up the incline student went
Because usually in projectile motion its a person throwing a ball and sometimes its arched at an angle
That means we need to find at what point the student lost all the energy and stopped
Well if the student stops then can I say K_final =0
Yes
So projectile motion doesn't work here btw
We can probably do something like this
W - drag force x distance = 0
I haven't encountered a problem where I had to find where the energy is lost at least not yet
And we find the distance
What's W here
Total energy
Yes
Is the distance here the goal distance
Yes
At that distance the boy loses speed and slows down
And stops
But maybe that's also wrong
I'm not sure how drag comes into play here I would need to know the density, drag coefficient, cross sectional area
We aren't given anything about drag
Yeah but if u read the hint it says surface is frictionless till incline
I'm tempted to Say F=-kx from hooks law
Are you saying this turns into a inclined plane problem with sum of forces
Unfortunately no
Can u screen shot the entire question
That is the entire question
It can't be
The hint gives more info then the actual question
Talking about part a
I think what i said about drag force should be valid in here
But we need stuff to find that
I think you are onto something it says coefficient of kinetic friction is 0.20
Ik
But we don't have the density or area
Density of air is kinda common but what about area
Maybe something like this
Btw at what point did u draw those components?
Acceleration in y should be 0
When you gave me the idea of it being like a inclined plane problem
No i mean on graph
That was always there
Cuz if so then the components are wrong
Blue circle is boy
What's uk
Coefficient of friction
And fk is friction?
I'm thinking solving acceleration and use a kinematic equation
Yes
Which kinematic equation u are going to use?
I don't know yet but I only know v_f
I got a=3.92 m/s^2
Im thinking we could do this
Makes sense because the boy isn't deceleration
but instead of drag force we use friction force
In this problem can I say something about the initial velocity?
But the floor has friction that means the boy should slow down not speed up
initial velocity is 0 when he was at rest
Like way in the beginning
Wait I'm thinking maybe
Force of friction = constant x force
Find friction
And then
Ke + Pe - friction x distance = 0
I'm not good at rounding but is 32.653 meters two significant figures
33.0
If I put 33 and it turns out its not right then I'll have one attempt left so not sure if I want to risk it
Maybe not
Close this one and reopen so it gets prioritize and ask about how to round off
Someone else might help
Lets go. You were right
Whose better
So it turns out all that vector stuff was actually right
Did you understand how I got the forces in the free body diagram
So I got the idea to solve for a_x because mainly from previous problems I've done. And a_y=0 because the boy isn't accelerating upward
But ax is horizontal should there be some theta stuff in here too?
The boy is moving on an inclined surface
Nvm the question is solved thats the good thing
!done
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I think this the hardest problem I've done ever
But thanks to you I was able to get an idea on how to solve it
.close
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is someone able to help me solve this? i need to minimize it with simplex method
I've tried it like 3-4 times and keep getting the same answer which is wrong so I just want to look at someone elses work or something and see where I'm going wrong
what have you tried
my work is messy but i can send it
That's trying the same question 2 times
and this is the actual answer so i dont know what im doing wrong
<@&286206848099549185> if anyone that knows how to do it can do it and show their work thatd be really cool cuz i just dont know where im going wrong
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I'm doing mechanics / maths at A level and in an answer it says initial velocity of A = final velocity of B (they are 2 particles connected by a light inextensible string over a smooth pulley)
Is it also true that final velocity of A = initial velocity of B because the string is inextensible?
do you have a picture?
offhand i would think their velocities are always equal (if you set up the coordinates appropriately)
what do the two a ->> arrows indicate?
acceleration in that direction
is that defining the coordinates for each block?
no there is no coordinates it's like suvat and I got the answer I was just wondering because Vb = Ua is Ub = Va
ok well if you define the velocities with the convention that block A's positive velocity points to the right and block B's positive velocity points down, then aren't they always equal? assuming the string doesn't stretch or compress
that's usually the assumption in this kind of problem
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i dont understand the point slope form. with y = mx+b, I can visualize understand each component. I have found no explanation of the corollary y-y1 = m(x-x1) form, other than that it is derivable through some algebraic manipulation and can describe arbitrary points against a given x1,y1 and slope. Still, the equation is meaningless to me when I look at it, and it seems most of the resources out there do not care about making it meaningful for students.
I mean it is just one step away from the original equation.
Ive only really used it for faster algebraic manipulation (sometimes) and some numerical methods when coding
$m = (y-y1) / (x - x1) \rightarrow y-y1 = m(x-x1)$
UsingApp
idrk waht u mean tho
So $y = m(x - x_1) + y_1$ and so the slope of this line is just $m$
south
Now if you substitute (x, y) = (x1, y1) into the equation, you get 0 = 0
So (x1, y1) lies on the line
And also if you have a slope and one point on the line
That determines the unique line: only one line is possible
why does y = m(x-x1) + y1
(If you get something like 0 = 2 then this is false, so (x1, y1) wouldn't lie on the line)
Add y1 to both sides
that does not mean anything to me
i want visual intuition not algebraic manipulation
We're just finding the slope of the line
Visual intuition and the algebra go hand in hand
Notice I didn't expand everything out
You just have to look at the coefficient of x
You see m(x + ....) so there is an mx term in there
And the rest are constants
y = m(x-x1) + y1 does not make sense to me
The reason for this relies on the visual intuition
because y - y1 = m(x-x1) does not make sense for me
What about this doesn't make sense
it means nothing to me. it is just letters
well m is just a ratio between change in y and change in x
Alright how about we expand it then
$y = mx + (-mx_1 + y_1)$
south
why (-mx
$m(x - x_1) + y_1 = mx + m(-x_1) + y_1$
south
that did not help
"the slope times the difference of the first coordinates of two points + the end coordinate of one point equals th slope times the first coordinate plus the slope times the negation of the other first coordinate..."
like, do you see how that is super hard to follow and meaningless visually
where I am at currently.
just letters, being re-arranged to be more letters. that doesn't do anything for me in terms of comprehension
The slope is m
You have to understand that the slope is just the number in front of the x
i know what all of the letters mean
The y-intercept isn't very useful I know
how they are arranged in the equation is not intelligible to me
"the slope times the difference of the first coordinates of two points + the end coordinate of one point equals th slope times the first coordinate plus the slope times the negation of the other first coordinate plus the other second coordinate"
i can't comprehend this sentence
first, the fact that x1 and y1 are on two different sides of the equal sign is very bizarre for me
like you two equations being mixed together
Okay so
We can let $(x_2, y_2)$ be anywhere
south
yeah
So we can just let $(x_2, y_2)$ be the point (x, y)$
south
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So by definition, the slope $m = \frac{y - y_1}{x - x_1}$
south
We just subbed in (x2, y2) = (x, y)
yes i understand that
Then just rearrange to get $m(x - x_1) = y - y_1$
south
$y - y_1 = m(x - x_1)$
south
So what this tells you is that the point-slope formula is just another way of expressing the slope between two points
Except one of the points is (x, y) where x and y are variables
rearranging it gets it into a form that does not make sense to me
You can always rearrange it back to this
the problem is that I want to understand equations not memorize them
And I'm telling you this
but it is an expression that does not seem comprehensible on it's own
y = mx + b is comprehensible on its own
zero algebraic manipulation required
right now my understanding is "these two forms are equivlanent, but I have no idea how this second form makes coherent sense and definitely could never derive it myself from scratch"
you multiply both sides by (x-x1)?
thats just the algebraic trick to switch between the two forms right?
deriving second form by manipulating the first form also does not feel "from scatch" either
we don't learn y = mx + b by first deriving it from the second form
we are able to learn it from first principles
is it not possible to do it the other way around?
derive point slope form before deriving point intercept
y-b=m(x-0)
this I also do not fully get
anyway, just going to memorize the point slope equation to pass the exam and then forget it forever. thats what american schooling wants me to do. hate algebra so much
otherwise I will spend 3 days searching for intuition-focused resources that do not exist. every single time I encounter an equation in preparation for my exam
you know (0,b) is a point
just plug x=0 to see y=b
and plug x=x1 to see y=y1 is also a point
LHS solve for m
RHS solve for b
then use both
ok step by step
y=mx+b
y-b=mx
even going from y = mx + b to y -b=m(x-0), makes me lose all semantic context
I just turn off my brain and go into dumb algebra mode "subtract by both sides..."
and am no longer thinking about the problem
but just stupid symbols on paper
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how do we get this factorization
i get expanding rhs proofs it, but given just the lhs as a function how would we factorize it
(not relevant)
Write this as $\frac{n^6 - 1}{n - 1} - n(n^2 + n + 1)$
south
there are innumerably many ways you can do this but without knowing about the factorization beforehand you wouldn't think it's possible
Then you can see (n^2 + n + 1) will factor
Yeah but it's all based on tricks
Like the question becomes 'how did you know to write it like that'
yesh i get this
:<
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(though not to be completely disappointing the complex number approach as mentioned by south does shed some light on this matter
for instance, you can deduce that x^8 + x^7 + 1 is factorable over the integers for the exact same reason)
Wow yeah I see it, that's amazing
numbers 🥰
math is brutal and fun at the same time
So yeah that generalises to x^(3k + 2) + x^(3k + 1) + 1
and you can replace one of the ks with a j 😅
.reopen
✅
Yeah I wasn't thinking of complex numbers at first
could i get some elaboration on this
By definition $\omega^3 = 1$
south
So $\omega^5 = \omega^3 \omega^2 = \omega^2$
south
So we have $\omega^2 + \omega + 1$ in total
south
$= \frac{\omega^3 - 1}{\omega - 1} = \cdots$
south
$= {\omega^2 + \omega +1}$..?
SirGareth
Yes, omega^4 = omega
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@crimson sedge Has your question been resolved?
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"A certain component is critical to the operation of an electrical system and must be replaced immediately upon failure. If the mean life of this type of component is 110 hours and its standard deviation is 30.5 hours, find the minimum number of these components to stock so that the probability that the system is in continual operation for the next 2000 hours is at least 0.95."
I don't know what equation(s) to use.
Time until failure is usually modeled with an exponential distribution
That being said, you're looking for the distribution of parts used within 2000 hours
Then again they are giving you the SD here, so they must not want you to use an exponential distribution
What class is this for?
Ah okay. We're assuming the time until failure is normally distributed
Then let's say we bought 20 of them. We can create a new random variable called the "sample mean" which represents the average time they all fail.
By the Central Limit Theorem, the sample mean's distribution is:
- Normally distributed
- Mean is the same as the original mean
- SD = σ/√n
Where σ is the original SD and n is the number of parts bought
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how would i find this
hmm
𝔸dωn𝓲²s
a = -7
𝔸dωn𝓲²s
So the question is which R makes sense
So that in either comes -4 out
-7 - R = -4
or
R - 7 = -4
yea I think the latter equation does more sense, I gave also enough hints lol
@kindred hornet Has your question been resolved?
lmao
based on R you figure that out
R is 3
ohh
the other equation gives us -3 which gives us the interval (-4,-10)
So the first one (-10,-4) does more sense
and since at x=-4 converges
it should be (-10,-4]
it says thats also wrong
then idk lmao
yeah its pretty weird
@kindred hornet Has your question been resolved?
a radius of convergence is a positive number...
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why is this wrong
but what im not quite sure is how between [-2, 2], this is not true
no no i mean f(x) could be a piecewise function *unless the problem/what youre doing says it cant be
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helloo how might i find the sum of this infinite series?
$$\sum_{n=1}^\infty{(\frac{3}{n(n + 1)} + \frac{1}{2^n}})$$
it is not a geometric series, and trying to find the limit of its partial sum formula with l'hopitals is much too hard to be the solution
declspecl
Perhaps partial fraction?
Looks like they are both positive so you can just split the series apart assuming it converges
the second best trick besides geometric series formula is telescoping sums, where you rewrite a fraction and hope almost everything cancels
here you can write 3/n/(n+1) as 3/n-3/(n+1), and when you write out a few terms of that notice that a bunch of things cancel out
ahh genius i totally forgot those existed... and did you get that rewrite through partial fractions? because i did get that through partial fractions but maybe you did something different
$$\frac{3}{n(n+1)}$$
$$n(A + B) + A = n(0) + 3$$
$$A = 3$$
$$B = -3$$
$$\sum_{n=1}^\infty{\frac{3}{n(n+1)}} = \sum_{n=1}^\infty{\frac{3}{n}} - \sum_{n=1}^\infty{\frac{3}{n+1}}$$
declspecl
yea it's like always with partial fractions
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how do you solve 5?
@nocturne ether Has your question been resolved?
you'd have to look at how the y column changes between values, like if it always went up by a number or doubled every time
neither of those are true though so there's another way to test if there's any polynomial fit, which is taking successive differences over and over
for second differences I got like 5.1 5.3 5.2 if that's what you got too
since those are about the same and on the second layer you'd say it's a quadratic fit
hmmm
okay i don’t think i understand
this is actually my brothers problem his book is giving a very weird and specific way of solving it
but it’s not working
like if you keep taking the differences
0 3 11.3 24.7 43.3
3 8.3 13.4 18.6
5.3 5.1 5.2
which means 5.2/2*x^2+bx+c is a decent fit
ohhhh
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What am I doing wrong? I have done this problem 4 times my paper is about to rip
is x = -1 in questionn no 11
You multiply 2x by (x+3) in the start
which is 2x² + 6x
Instead of 5x
And secondly the -(x²-9) bracket
after you subtracted the x²
it became -9 leftover
but it'd be +9
since you have - times -
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Why cant a polynomial ring be a field? The classic explanation I see is that f(x)=x has no inverse, but in a prime field wouldn't the inverse just be x^{p-2} given by Fermat's little theorem?
your coefficients are from the prime field
x is an indeterminate so any multiplicative inverse is going to end up being x^{-1} which isn't a polynomial
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say Z_5[x], do you consider the p(x)= x^3, q(x)= 1 same?
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Hi
Yes
y = F(x) right?
If the answer is yes, then everything is in order
@light inlet Has your question been resolved?
Yee
Alr tyy
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so, i need to build this natural succession such that a_i = 1/(4i +2), a_(i+1) = 1/(4i-2) , a_(i+2) = 1/(4i-6), a_(1+3) = (4i-10) ... and so on but my issue is, since the 4i is always constant i'm having a lot of issues to come out with the succession, is it even possible to build such succession?
the reason i want to find such succession is that in for this exercise, using the topmost property which i already proved should be sufficient to prove part iii-)
since part iii-) 1/((2i-1)(2i+1)) = (1/(4i -2)) - (1/(4i +2))
if i manage to find a succession a_n such that a_i = (1/(4i + 2)) and a_(i+1) = 1/(4i - 2) then i'm done
for part II-) it was easy, just let a_i = 1/i but part 3 is trickier
a_n = -1/(4n+2)
then a_i = 1/(4i + 2) which i want, but a_(i+1) = 1/(4i + 6) which i don't
ugh, let me think about it for a minute
i don't understand how a_n = -1/(4n+2) would help me solve the exercise, sure i can get a_i = -1/(4i+2) and put it in the sum but when i put a_(i+1) i don't get the expected result to put inside the sum to follow the topmost "theorem"
why for the second exercise i could just make a_n = 1/n to get both a_i = 1/i and a_(i+1) = 1/i+1 but for this one gotta use some a_n = something but both a_i and a_(i+1) doesn't get me what i need for what's inside the sum?
I don't understand your question
here, you can check that a_(i+1)-a_i gives you exactly what's in the sum
oh, i see it now, i wasn't thinking about it right
i had to find a_n such that a_(i+1) - a_i = (1/(4i -2)) - (1/(4i +2))
how did you find a_n by the way?
your formula basically looked like a_n=1/(4n+2), it was just inverted (hence multiplying by -1) and indices shifted by one (hence a_n=-1/(4(n-1)+2) = -1/(4n-2))
alright, thanks for the help man, i was stuck with this for almost an hour, i've been learning about induction for 2 days and it involves a lot of successions and the like
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P
There are 2 groups, namely group A and group B. Group A consists of 6 men and 3 women with an average height of 168cm. Group B consisted of 3 men and 6 women with an average height of 160cm. If male students are taller than female students, which of the following changes would cause the difference in the average heights of the two groups to be the smallest?
(A) Move 2 boys from group A into group B and 2 girls from group B into group A.
(B) Add 2 boys to group A whose height is the same as the 2 boys in group A.
(C) Move the 2 shortest women from group B into group A
(D) Move all males from group A into group B and move all females from group B into group A
(E) Add 2 women to group B whose height is the same as the average of women in group A
Anyone have an idea?
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<@&286206848099549185>
@crimson sedge Has your question been resolved?
Average height of women - 152 and men -176(hope u can do the rest 
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confused
q ^ 0 = 1 if q≠0, so you get p*1 = 10
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Someone explain pls
do u know long division?
Yh
ok so divide x^2 by 16x^2 + 1
Oh because the numerator has a polynomial power equal to the denominator?
yes
Ok I will try that
for partial fractions the polynomial power of numerator needs to be lower then denominator
But I dont understand something
I tried to integrate this equation with a substitution
And I got a different answer
which substitution u used?
Why, all I did was square the top and bottom
JustToPro
4 = 2
if u are squaring something , u need to take a square root
$$2 = 2$$
$$(\sqrt2)^2 = 2$$
$$2 = 2$$
JustToPro
Bruh i dont get it
do u know why we can divide and multiply a number ?
Why
well cuz we are also doing the inverse
division is inverse of multiplication
same way if we are doing square root we need to inverse it
and inverse of square root is square and vice versa
well whatever , u sub doesnt work here
trignometric sub works here
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what happened in the numerator
factored out 2^n
ℝαμΩℕωⅤ
oh sorry the 2n should be 2^n
okay okay ty for pointing that out, you may have saved me from a couple minuses there
tyvm!
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Can someone help me with validation to an answer?
well i've been studying AP and stumbled into the fact of transforming an AP into a series of sums, making every term of the AP equal to the terms on the sum.
like how the upper limit of the sum equals a_n and the number shown in both terms are equal
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n choose 6 = 28989675
any clever way to do this by hand other than bash
tried using the algebraic formula for n choose k but like you just get that
n(n-1)(n-2)...(n-5) = 720 * 28989675
idk I had it in a contest td and had like 5 mins
with a calculator?
that wouldn't help much i guess
,calc(720^(1/6))(28989675 ^(1/6))
Result:
52.47220410016
no calc lol
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does this equal square root of x

This is x^2/4 so yes basically sqrt of x
$\sqrt[m]{x^n} = x^{\frac{n}{m}$
TayBee
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
is this function the same as y=sqrtx
Yes
how come the domain of the first function is all real numbers while the second function is x >= 0, x ∈ R
Because if you square a negative number it becomes positive
Which expands the domain to include negative x
But sqrt(x) doesn't have that luxury
Remember the domain of the square root is all non-negative real numbers
Yeah
Identical for non-negative x, only defined for (x^2)^1/4 for negative x
Your root would be equivalent to $\sqrt{|x|}$
TayBee
In terms of domain
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so finish the problem but its wrong anyone can tell me why
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I need help
I think he died
lol
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Hey, how would i switch the bounds for this? I assume you have to since cos(x^2) is an impossible integral?
Sorry to whoever was about to help me an hour ago with this, my computer totally stopped working
The z is independent so you can do it first
Then it becomes a double integral
Plot the region defined by bounds of the double integral
And use that to swap the bounds
How can I just do the z first without changing the bounds of the inner integral?
well you use the z bounds for the integral
but notice the z bounds don't depend on x,y and the x,y bounds don't depend on z
hmm, ok so you can just move the z bounds to the front but since x depends on y, that's why you'd plot the xy bounds
Yeah
Integral bounds define your region in a very natural way: here it's 0≤z≤4, 0≤y≤1, 2y≤x≤2
you can swap these bounds around any way you want and they still define the same region
And if they don't depend on each other, then you can evaluate them in any order
ok that makes sense
yeah
thank you!
np
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trying to understand this question and i dont understand what to do man 😭
May I assume correctly that you know how to do derivatives?
@steep steeple Has your question been resolved?
for the most part yes
sorry for the delay in response
stomach decided it was time to kill itself
Do you understand what the implications are for a derivative to be positive, negative, or zero?
I do not directly recall
The derivative can be used to calculate the instantaneous rate of change of a function (IROC) at any given point of the function.
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can someone please explain why we don't draw the negative part of the graph ?
and also do we always integrate from the axis to the x intercept? I am a little confused on how to figure out the bounds of integration
4-x^2 looks like this, we dont really need the negative bit because we're just examining our enclosed area
and this depends on what the enclosed area is
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how to do
Can you think of any examples, or counter examples?
wait for arc length u just take a particular cross section and find arc length of that right
The arclength is just the length of the curve. Here the curve sits on the unit sphere.
What kind of simple curve has, say, length 2pi on the sphere?
radius 1 circle
Yeah, so any great circle / meridian right?
Now, knowing such a curve has length 2pi, are there curves that are longer?
so if the curve covers the entire sphere then the arc length is just the volume
which is 4/3pi
wait nvm
wait yea
i meant arc length is just the surface area
which is 4pi
It's a nice idea, but it presupposes that such a curve even exists, which isn't particularly trivial.
ye true
There is simpler. If we know that a meridian is a curve of length 2pi, can you imagine any curve longer than a meridian? (Hint ||a meridian wraps once around the sphere||)
one that wraps multiple times
Yeah
is there a limit to how big the arc length could get?
so its false
Well just from this construction, you could have it wrap around as many times as you want, so it should be as big as you want. If instead we want a curve that doesn't intersect itself, then you could imagine a spiral that wraps around the sphere, that would also be > 2pi
ty
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won't be anything that covers "ALL" / the entirety of currently known math
I think they were saying that as in there isn't going to be a book that covers all levels of math
mainly since math diverges into different "categories" and even "sub-categories" of mathematics
something like what
This was pinned in #calculus
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I am currently confused on how mw^3 got into the denominator. I understand that when condensing or expanding, subtraction is division. But there is subtraction between log m and 3log w, so is it not division again?
it is division again
that's what you get when you divide again (after applying power law for the 3log(w)
its not
$\blue{5\log(p) - \log(m)} - \red{3\log(w)} + \log(p)$ \
$\red{3\log(w)}$ is being subtracted from the $\blue{5\log(p) - \log(m)}$
ℝαμΩℕωⅤ
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Can someone explain my mistake?
sin^2 - 1 isnt cos^2
u = sec , works here
wdym?
thats wrong too
shouldve been x = sintheta
ah man i think i keep mixing them up
i'm going to try doing them again, can u stick around for 10 mins or so?
sure ping me
why is this wrong ? @peak minnow
dont know
seems correct tho
just that why is there still a 9
when we already have 9/9 which is equal to 1
oh right but when i submit it without it's still wrong
ok i see it
what is it
sec theta is x/9
yea
ok , gl
can u still help me if i struggle w smt if i ping u
ok
Do you know where i messed up ?
seems fine
what do i do now?
integrate the cos/sin and use ur value of theta
cos/sin = cot btw
wait found another mistake @dense peak
wehre
do i use powers of trig to break up sec^3theta or just make it sin over ocsine
i think i messed up somewhere
doesnt seem like it
it was wrong when i submitted it (these are just practice questions, so no penalty)
it was wrong
hm
i think i messed up somewhere
can u send the question?
that isnt the question u sent tho
yeah here write $\sqrt{x^2+9} + c$
JustToPro
and check fi that is right or wrong
it was wrong
,w \int \frac{\sqrt{9+x^2}}{x} dx
ok we are off by just the 3 tanh^-1 (.....)
yea how tho
,w d/dx -3tanh^-1 (\frac{\sqrtx^2+9}}{3})
,w d/dx tanh^-1 (\frac{\sqrtx^2+9}}{3})
ok what ever
to me it looks fine but idk why its wrong
JustToPro
I tried this
what did u let u equal to?
me neither
close this one and open a new one maybe , someone better might be able to help with that
do yk this one
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find
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Why are these equality valid?
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i got the wrong answer. my working was:
r^2 θ = 57.6 => 1
r θ = 12 => 2
1 / 2 => r = 4.8
r = 4.8 -> 2
θ = 2.5
r^2 theta is not 57.6
that would be 115.2
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can someone help me with this question i'm not sure why you times the sectors degrees by six and why you need the arc for that specific bit
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I have no idea how to start solving this
use angle addition formula
what is that
im not native english so it might have another name for me
the 2nd is leg is just 1?
ye
You have to solve for x right?
yep
$\sin(\alpha\pm\beta)=\sin\alpha\cos\beta\pm\cos\alpha\sin\beta$
you can theoretically substitute sin(x) with sqrt(1-cos^2x) and then solve but idk how easy that is
فطر
uhh
could you simplify that
wdym simplify this is the formula
i will try that
no
what will that do here?
too complicated
oh ok its this
maybe but you can
divide each hand by some number such that angle addition formula is applicable
not even too complicated. you get the cos sqrt3/3 from the other side and then ^2 both sides and you have a 2nd degree polynomial if you just set cosx=u
what is alpha and beta in this context
angles
theres actually a really fast way to solve these type of questions
namely $a\sin x+b\cos x=c$
فطر
divide each hand by $\sqrt{a^2+b^2}$
فطر
then it will match up with the formula perfectly
Yea this is probably the right method
i was taught this method during my trig chapter and its one of the best thing i learned
so what to divide with?
but anyway, try this
reading comprehension 0
doubt so, i firmly believe mine is more useful for a wider range of these type of questions
but im no socrates, i am here to help, not to argue
well if it is only this type of questions then subsituting sin with sqrt.... always solves it
@timid sparrow
sure, tell me how it goes
in this particular example its not even a second degree polynomial as the 1 from each side will cancel out
i didnt say its a second degree polynomial what
no my question wasn't solved
nah i said it, and i am just now saying that it wont be
!occupied
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i got to this
