#help-0
1 messages · Page 603 of 1
same thing
Huntifer
Yeah
$-8x^{-5}$
Huntifer
Next one
Wait no
$-\frac{8}{x^5}$
Huntifer

Sorry I feel dumb
Azaradichta
Oh wait it's 9
$$\dv{x}(-3x^{-3})=3\dv{x}x^{-3}$$
Azaradichta
$$\dv{x}(x^{-3})=-3x^{-4}$$
Azaradichta
Overall,
$-4*2x^{-4-1}$
Huntifer
applying power rule to 2x^-4

Huntifer
yeah
😅
$9x^{-4}$
Huntifer
Yes
-4
Yeah
And then just write everything together
$-8x^{-5}+9x^{-4}-4$
Huntifer
The above one is correct as well
In calc, you will encounter such things most of the time, the question having multiple answers
For example
Yeah I know, the testing thing we use only wants it one specific way though
so it'll fail you on a question if its in another form
for example
it wants it like this
$$\dv{x}\left(\frac{x}{1-x}\right)=\dv{x}\left(\frac{1}{1-x}\right)$$
Azaradichta
That's the thing for online, right?
yeah because 1 and x are interchangeable in those cases
Teachers don't mind this
They both differ by 1
never doing this again
lmao
online college bad
Granted I didn't have a choice

So power rule applies with D too?
D what?
You just do the same thing to the thing as before
so its
$\frac{5}{x^{2/3}}$
Then
No
oh wait
2/3
2/3 sorry
Yea
Huntifer
yes
Huntifer
Then power rule
$$\sqrt[n]{x^m}=x^\cfrac{{m}{n}}$$
Azaradichta
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
Wow it doesn't work
As yes
I have to change my preamble

I swear to god
imagine
non-existant numbers
we are moving past imaginary
we are now using non-existent numbers in our calculations

5x^-2/3
Yes
so now
what does cfrac do?
$-\frac{2}{3}*5x^{-\frac{2}{3}-1}$
Huntifer
It creates fractions like ½, ¾ etc.
I thought the bot included it's package
ah $\cfrac{a}{b}$
But it didn't
zslya
huh

So, it should be -2/3 - 1 = -5/3
Huntifer

Nice emoji, I don't have nitro 
^this one
Kk
Yeah it's correct
Congrats! You just acquired Level 1 knowledge of Power Rule!
it is correct
Orz
Huntifer
Ofc
I get a B if I get just 25% on the exam tomorrow
So I'm not SUPER scared but
Pretty scared because I'm looking at this review and drawing blanks all over the place
Ahh I see the purpose of cfrac now @alpine sable
be careful with powers the computer is stupid
So
$\cfrac{2}{1+\cfrac{2}{1+\cfrac{2}{1}}}$ vs $\frac{2}{1+\frac{2}{1+\frac{2}{1}}}$
If you're still around, here are some dummy ones
zslya
hmm?
You got to apply chain rule
what is dfrac now 
Yeah
It's short for \displaystyle\frac
f(g(x)) = f'(g(x))g'(x)
Ah
I can't do that in the form its in tho right now right?
If you don't use LaTeX on pc or somewhere, then you won't understand the usage of displaystyle
For a
Actually..
Can't I apply the same concept to A?
As with the power thing
Let $u=4x^2-4x+3$. By chain rule,
$$\dv{x}f(x)=\dv{u}f(u)\cdot\dv{x}u$$
Azaradichta
Makes more sense if you let y=f(x)
I use latex on mac
$1(4x^3-4x+3)^{-3}$
Huntifer
I know this is probably ghetto but
what is √(2) times 2 exact value? forgot the rules
Pretty sure its not a real number and is a decimal
It's just $2\sqrt2$, or $2\cdot2^{\frac12}=2^{1+\frac12}=2^{\frac32}$.
Azaradichta
$$\frac{dy}{dx}=\frac{dy}{du}\frac{du}{dx}$$
So I'm assuming the way I tried it above was wrong?
Azaradichta
Yeah everyone knows power rule and Chen lu
When did you try?
I mean what?
$1(4x^3-4x+3)^{-3}$
Huntifer
This monstrosity
$\dv{y}{x}$ hack
1u^-3
zslya
or just u^-3
Yes

Now use Chen Lu
Chen lu...?
Chain Rule
Is that a martial art I don't know?

bruv
$$\dv{y}{x}=\dv{y}{u}\dv{u}{x}$$
Azaradichta
^ Chen Lu
the chain rule I have is
Azaradichta
Huntifer
I just put f(x)=y and g(x)=u
So that it makes more sense👍🏼
You can think of it as dividing and multiplying by du
$$\dv{y}{x}=\dv{y}{\textcolor{yellow}{u}}\dv{\textcolor{yellow}{u}}{x}$$
Azaradichta
Azaradichta
Yes
$$f'(x)\equiv\dv{y}{x}$$
Azaradichta
When I think of f(g(x)) I think of
3(2x^2+3)+3
As an example
Where f(x) is 3x+3
And g(x) is 2x^2+3
$$f(x)=(\underbrace{4x^2-4x+3}_{g(x)})^{-3}$$
Azaradichta
and $f(x)=x^{-3}$
Azaradichta
Yes
I always forget that exponents can be the outside formula sometimes
sorry
so in this case
derivative f(x) is
-3x^2
Yes
Yes!
Yeah
💯
I was getting confused by the fraction thing
Because I have to see everything in numerical use, the conceptual stuff with derivatives confuses me for some reason
You will get it with time
So at this point I see d/dx and I'm just like, ah yes, its telling me to differentiate, I know that
Yeah
So in this case anyways
Remember the Liniati Lu, Pawa Lu, Koshan Lu, Chen Lu,
-3(4x^3-4x+3)^2 for the first part
Yes
Yes
oh oops
Huntifer
Yes
whered u get these
So the reason you use u is just so you can simplify it easier then substitute after?
On bprp, Papa flammy, Dr. πam channel
You don't need to think about it, I suppose.it will just confuse you more
Well so like
Use the fg form as of now
$-3(u)^2(12x^2-4)$
Yes
Huntifer
So uh
$-3u^{-2}\cdot u'$
Azaradichta
Anyways, bye
Because I also have to do my work
Cya later @shadow sparrow
also add me as a friend if you don't mind
lol, no worries, yeah I'm praying I can manage tomorrow, we'll see, tyvm for the help!
did do
At the very worst
I get a C tomorrow
Thanks

Good luck
yes
don't multipost. i answered you in #discrete-math
How do I go about showing that:
$$ \partial (B_\epsilon (x)) \subseteq { y \in X : d(x,y) = \epsilon } $$
Cursor
I'm guessing I do some sort of contrapositive here
i mean you could?
you need to show that a point on the boundary of B_ε(x) is exactly at distance ε from x
you can instead show that any point not at distance ε from x is either in the exterior or the interior of the ball, depending on whether it's further or closer than ε
Mike is running towards the last pie for sale at the school bake sale. Jack see Mike running and Jack decides to sprint for the pie. Mike runs at full speed, 5.3 meters/second, while Jack speeds up at a rate modeled by the function 1.5x^2 + 0.3x. The pie is 25 metes away from Jack when he begins to run. Mike is already 4 meters ahead. Who reaches the pie first? Explain how rounding an exact answer could affect the results.
^ this person is getting help in #help-9, whoever wants to post their question can go ahead
hi
i'm having trouble understanding the concept of instantaneous rate of change
my confusion is similar to the arrow paradox
how can there be a rate of change where there is no change?
i could calculate the rate of change of the line y = x
the instantaneous rate of change is not by itself a "bona fide" rate of change
rather, it's what you get in the limit as you take average rates of change in your function over progressively smaller intervals containing your point
so nigh-instantaneous is a better term?
no
actually, 3b1b has a video in his essence of calculus series which addresses this very issue
What is an "instantaneous rate of change" when change happens across time?
Help fund future projects: https://www.patreon.com/3blue1brown
This video was supported in part by Art of Problem Solving: https://aops.com/3blue1brown
An equally valuable form of support is to simply share some of the videos.
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$\sqrt{4 \times 7} \neq 4 \sqrt{7}$
Ann
if you wish to put it that way.
okay, that video cleared up a lot of confusion
so it is indeed as he puts it, sidestepping the paradox
sneaky human devilry
i love it
where did the n go lmao
1/n appoaches 0
yes
Ah
i figured it out thx

You can remember like this
Imagine n as largest number possible as you can
Like n = 1000000 , then 1/n = 0.000001
And you can already see how close it is to 0
And as you increase the value of n more and more 1/n will go more close to 0
ahh
that makes a lot of sense
thanks
yo I was doing this problem
and i am not gettting how 1/4 got in
where's the rest of it
4 * 1/4 = 1
they're making preparations for chain rule
(without explicitly making a substitution)
Is the channel free ?
yah
So i got to calculate the area of AMH
And i have something with x^4 at some point whereas f(x) doesn't (which is the area of the triangle)
The functions aren't translated correctly so check for the one upper
Anyone, help me ? Thanks <@&286206848099549185>
assuming the graph lines are equidistant, you can find the x-value for M and plug it into the parabola function to find the y-value
with that you should have enough information to do 1/2bh for the triangle
Like i have to look for which x the y = 7 ?
What's the question? Solved already?
can someone help me out with this question.
I wanna know how do i calculate the area of AMH / where was i wrong
Pic? @slender turret
Got it
Can I know what data is give?
The equation of that parabola is provided
The coordinates of A and B are given
I want the equation of the line AM
Is it given? @$name#9275
A(-6; 0)
B(6; 0)
area -> f(x) =
$f(x) = -\frac{1}{9}x^3-\frac{2}{3}x^2 + 4x + 24$
^anyone
you are already dead
What is this? Equation of that curve?
I have to prove that area is f(x)
of the triangle area
they say
I've done that but ion know why it seems bad
it is bad cause i have $x^4$
Can you translate the whole question?
I fell like you're missing something @$name#9275
you are already dead
a/ Show that the area of the triangle AMH is equal to f(x)
b/ Calculate f'(x)
c/ Study the variations of $f$
you are already dead
d/Find the coordinates of M for which the area of the triangle is maximum and precise this area (number)
<@&286206848099549185>
Is this the equation of the parabola? $y=-\frac{2}{9}x^2+8$
simply.nikhil
you are already dead
you are already dead
Oh wait. Now I get it
cause @surreal meadow said i could find the x directly but i think because of my english i didn't understand well
Give me a min
kk thx ^^
$\text{Area}=\int_{-6}^{x}\left(-\frac{2}{9}x^2+8\right)dx$
simply.nikhil
You'll get the answer when you solve this @slender turret
wow xD ion even know what's that
What?
we didn't see that in school for now
it's next year i think
but is it hard ?
like maybe if i put this as an answer nothing is wrong since it's correct ?
Piece of cake if you pay some attention 🙂
so what that symbol is called
Integration
is it basic level of integration ?
There are two types of integration. Definite and indefinite
The one I've written above is definite integration
using x in bounds and as an integration variable 
Holy shot. Scratch that @slender turret
The problem isn't just solved here. It further goes on
I've missed one more part
mmh
Dude
This is the most simple problem that I've ever scene. But as soon as I saw a parabola and this equations, I thought about integration. Which is absolutely unnecessary here. @slender turret
$\text{Area of triangle}=\frac{1}{2}(base)(height)$
simply.nikhil
Use this formula for that triangle and you're good to go
yeah but i can't find the base and height i gotta use vectors right ?
Base is AH
From A to origin it's 6 units
And from origin to H it's x units
So AH=(x+6)
Understood?
Nope.
Here that's why I asked you the coordinates of M or H
But when I read the question I got to know that the point M or H are not constant
The coordinates of M and H are variables
H(x, 0) and M(x, y)
simply.nikhil
yes
From the origin H is x units away in x direction and 0 units away in y direction
From the origin M is x units away in x direction and y units away in y direction
Now you understood this?
Forget this. Not necessary here
Yep
so in mathematical way how i describe Area like A = (...) ?
$Base=(x+6)$
$Height=\left(-\frac{2}{9}x^2+8\right)$
simply.nikhil
yup
the thing is i had (x + 6) ^ 2 for base
before
and height again same
square
You've this formula
i messed up with the formula
Sometimes shit happenes. Dw about it
$\frac{(x+6)(-\frac{2}{9}x^2+8)}{2}$
you are already dead
Solve this and you'll be at f(x) in no time
for real ?
Ofc
Ah ok ( i didn't know english say this expression too )
for real
I'm not understanding what you're trying to say
Let it be
Have a good day bro.
I gotta hop now
How do I find the sfa and volume of a cylindrical tank with height of 15m length of 7m and half sphere on top?
Oh and it has a bottom
This my formula for volume pix3.5^2x11.5+(4/3xpix3.5^3x1/2)
Is this correct?
Hahahaha
LOL
This chat just turned sexual so fast
Nope, it's just belly
Am i okay to ask a question in here?
no
Anyone able to help me out with this at all?
I have gotten it down to (c^15/c^-3)^1/2
I'm not sure where to take it from there. I'm not too sure if i have done it right so far?
This is essentially what i have gotten it down to
yeah.. so keep simplifying
Once it got to this point, i'm not actually sure what i do next @glass lichen
apply the other index rules
$c^{-3}=?$
abe
Index rules isn't my strong suit, i was thinking that i remove the c^-3 so i just have c^12
15-(-3) isnt 12
you can either diretly use the divisibility rule
or the multiplicative one
if you convert it to 1/^3
i'd do the former tho
since its direct and faster
@carmine lion So it would be c^-1/3 ?
$c^{-3}=\frac{1}{c^3}$
abe
Yeah. That's what i've done until here. I looked at the one you just posted actually, but i thought not to do that because then it's like C^15 / 1/C^3
I'm not really sure honestly, it's a mess for me in this part 😅
$c^{15}\divisionsymbol \frac{1}{c^3}$
moshill1
@carmine lionAh okay, i get it. Thanks so much for that 🙂
if there is multiple fraction signs
try converting some to div signs
and see if that helps
can u help with a trig proof lol
$\tan(2x)\cot(x)=1+\sec(2x)$
abe
should i convert the LHS to sine and cosine
I mean my gut is work on RHS
cause I cant see a direct path from LHS
?
ok so how would i do it
$\cos(2x)=2\cos^2(x)-1=\cos^2(x)-\sin^2(x)$
moshill1
$1+\sec(2x) \ =1+\frac{1}{2\cos^2{x}-1} \ =\frac{2\cos^2(x)}{\cos^2(x)-\sin^2(x)}$
moshill1
yeah i got to this step
so then you can divide num and denom by cos^2
i get 2/1-tan^2(x)
ah i see
Yeah I feel that going right to left is easier, because if you did left to right you'd have to split the fraction by doing +1-1 on the numerator
There's no rare case
you should start from the side you think is better to start on, for me that was RHS
alright
will keep that in mind
Would someone be able to help me with integrating this please
(a/b) (x/b)^(a-1) e^(-(x/b)^a)
Probably easier if I just send a pic
(Done it now and got c - e^(-(x/lambda)^k)
: The square of the cube of the square root of the square root of 16
can someone help
sq(cube(sqrt(sqrt(16))
oh ok thanks
np
is the answer 512
$((\sqrt{\sqrt{16}} )^3)^2$
Darkness
oh Sq and cb are ^2 and ^3 didn't know
,ask ((√(√16))³)²
Nope
256
you basically multiply the exponents
then put the roots in exponents
sqrtsqrt(16)^6
64 ?
ok thank you
basically 4throot16^6
thanks
$$2018^{8012} (mod 7)$$
Hyl1s
how can I calculate this by hand
all I know is $$2018^{8012} (mod 7)= 2^{8012}(mod 7)$$
Hyl1s
you can find the cycle of remainder for smaller powers manually, e.g. 2 mod7=2 4 mod7= 4 8 mod7=1 and finally you get 2 mod 7=2 again , find where the 8012th power lies and you'll get what they are asking for
uh
i want to make sure i do this right
Find the value of x
i think the answer's 42
that is correct
so it is 4
nice
2^8012 mod 7 is 4 yes
then it works
btw this is right too right?
yes
what is your reasoning?
idk i think thats how you solve it
what was your reasoning for the last problem?
can you interpolate a similar logic here?
what angle would 31 be?
x
is x the third angle in the triangle?
yeah
it is not
how would i solve it
yes
could have done that as well
does remainder increases by 2 multiple when divided number is increasing ^2?
I don't understand wht you mean elaborate
if x/10=y(remainder 3)
then x^2/10=z (remainder 6)
are you asking if y and z are equal for every value of x?
no no i want to say that if x increases multiple x (^2) then remainder increases by multiple of 2
if x/10=y(remainder 3)
then x^2/10=z (remainder 3*2)
are you saying x^2 mod m = x+2 mod m?
x mod m = x^2 mod (2m)
oh
that is incorrect but can you explain your reasoning?
Hyl1s
but x cant be 4 and 5 bcs x>23
without putting numbers to x how can i find the value of x
x(mod9) can only take values from 0 through 8 you could manually check for what value of x<9 we get x^2 mod9= 7 and then find the minimal x x>23 for which x mod9= that x
why x(mod9) can only take values from 0 through 8 ?
what does x mod9 mean>
can you divide a number by 9 and get a remainder of 10?
right so you'll only get numbers from 0 to 8 as remainders when dividing by 9
do you know which angles are equal and which angles' sum are 180
2 and 6
4 and 75 degrees
yes
which angles are opposite
7 and 8 1 and 2 3 and 4 75 degrees and 6
wait a min is this a test
yes
no
if A*A=1156
how can I get A?
Sqrt(1156)
+- sqrt(1156)
,w sqrt(1156)
Thanks! I think i'm dumb
Right it is positive 34 and -34
is this channel free
Yes
I think
ok ty
I need help on this problem
I know that the volume of the barrel is 20 pi
and a.) is 10 pi
I don't understand b and c
What class is this for?
geometry
i have to do homework challenge problems
and i have no clue how to do the problem
Just wondering because my first reaction is to use calc but not if it is for geometry class
dang
No it isn't
Hi beautiful 🌚
bro?
I'm not sure how to do it without calc
What does special mean?
like 30-60-90 triangles
Oh ok
not really @golden quarry
is this correct or incorret
k
the radii are different
Wait wdym
they want you to figure out the area in 2d of one slice if you look at the circular part
Or u can use squares
thats the difference
sry i don't understand
when you take a slice of cylinder you get a circle right?
yeah a slice parallel to base
yeah that was what I meant
in this case it would be a circle with less than half filled with water
the portion that is filled by water will have some area
we have to find that area
do you think you can take it from here?
since part 3 and part 2 are essentially the same problem but with different values and different hints their might be a trivial solution I am missing , let me think
but saying a special triangle and trigonometry
is the same thing in a way
if you get the angle that the chord makes at the center you can get the area of sector and subtract the remainng area which would be a triangle
I can tell you the answer is 20pi/3 - 5*sqrt(3) but that is using calculus
I dont know how else to do it
oh ok
I am joking
ill try to use this process
I need help with something in questions 1 😦
wdym by angle chord makes at center
if a is the chord alpha is the angle the chord makes at center
this is kind of a stupid like quick question but i cant find this online, what does | | mean in set theory? as in if i had a statement like | A | = | B |
Cardinality
The number of elements that belong to that set
ah ok
so like
whats the difference between intersection and subset if its a set of one element
is the other thing im confused on
like A = {1,2,3} and B = {2} would A (upside down U) B = 2 and B C A be true
also thank you
im not rly good at math im doing this in the context of linguistics and was having trouble reading stuff
Always forget about this
And yes $B \subset A$
Max Hetfield
Can anyone help me with 3 questions on my algebra assignment
Just ask
Ok
So the circumference is pi x diameter
yes
The diameter is 6, bc it’s 2 x 3
yes
So the circumference is 6pi
So just work that out and see which one is closest to your answer
@slow mason
I need some help
Examine how a sum figure with five fields must be filled in with the expressions n, n + 1, n + 2, n + 3 and n + 4, in order to make the sum horizontal and the sum vertical as large as possible.
Sum figure: Must give the same number horizontally and vertically. One number must be part of both sides.
@alpine sable what's a sum figured
Nvm it was easy
which formula do i use to find the circumference of this circle?
I think so
so you know it's L
which means that you're only looking at the column of L
all other columns are not relevant
this is literally not the place for any of this
@dusk panther do you think you would know if you know you only have to look at the first column?
I’m not sure I thought that I would have to look at pretty much the chart as a whole to get the answer
no
cuz given L
means that only the first column is relevant
cuz the second column is only M
and the last column is L + M
Oh yeah that makes sense
Guys i have a question
How can you speedmath in division
There's people that can divide a very large numbers in seconds
I bet there's a trick. That only those who had graduated in a speedmath course.
I’m sorry I wouldn’t know
@dusk panther i really do wonder lol
Like i can multiply big numbers in my head using 30 seconds
But i rly do wonder how they can divide.
there's some tricks but a lot of it is practice and innate skill
the work the missing the right edge
Why is not a relation?
cause it passes the vertical line test
Functions are also relations
Yeah, im aware
How would I find s and t, if I have [x,y,z]=[4,7,-1]+s[4,8,-4] and [x,y,z]=[1,5,4]+t[-1,2,3]???
@dire dove set the [x,y,z] equal then compare the i j and k components separately to get 3 equations
2 of them allow you to solve for s and t
then use the 3rd one to confirm
Erzis
how can I be sure that both sides are either bigger or smaller than 0?
,w x'=x+t^2






