#help-0
1 messages · Page 720 of 1
,, u_x(y) = \frac{\partial}{\partial x} u(y)
uhhh
is u(y) constant?
these calculations add c to the equation which im supposed to solve
thats not intergate?
no
the velocity of the fluid
so no equation for it
yea thats what im supposed to do
u2-u1=u3-u2....?
huh
yea so i definitely integrate in this problem
thats how it works
so i find it weird that you guys find that weird
mental illness
.....wat
Hi, i really want to study english math but dont know where to start can someone help me pls?
what do you mean by "english math", like "math in english"?
Yes correct, i really want to study abroad
hmm Khanacademy is a pretty good resource for studying math in english
Do they charge money tho?
Khan Academy is free
Got a question, why do we write dy/dx when it’s actually delta x that tends to 0 and not delta y
Because doesn’t “d” imply some very very small quantity
(d/dx) y
Oh
What’s the d doing alone in the numerator
Or is that just notation
For taking the derivative of y = f(x)
well\
we also have integrals of functions of x like $\\int x\diff x$
Yeah
dy and dx are also called differentials
Yes
you can integrate a derivative, both with respect to x
Yeah
I also wanted to ask uhh when we limit delta x to 0
Why doesn’t delta y also tend to 0
It’s hard to grasp this
Also is it possible to have an infinitely large change in y when dx tends to 0?
e.g. $\int x\left(\frac{\diff}{\diff x}\right)\diff x = x$
Well delta x limiting to 0 would mean that there is a very very very small change in x
So shouldn’t that cause a very very very small change in y
Ah
Makes sense
Wdym
If you are far along a vertical asymptote then the y values are increasing rapidly wrt to x right
dx tends to 0 doesn't mean x approaches a value where the function is asymptotic
Yeah so how do we show that delta y also doesn’t tend to 0
If the change is very very small
why shouldn't it?
if there is a very small change in y then that means delta y is very small, i.e. close to 0
thanks
ez answers 
lol
wait
is that a property
is log_9(m) = log(m)/log(9) a property
wait
oh nvm
i got it
are you guys finished?
Given a deck of 40 cards of 4 seeds with 10 cards each of values:2,3,4,5,6,7, J, Q, K, A, what is the chance of drawing 5 cards of distinct values?
@old cobalt What they mean by rearranging is that u isolate "x" by algebraic operations
quadratic formula is the same thing but the rearranging is already done
Thank you 🙏
anyone?
<@&286206848099549185>
So 1st draw doesn’t matter, then 2nd draw has prob (39-3)/39, 3rd draw has prob (38-3-3)/38 and so on
Multiply the probabilities together and you get the answer
I did try something like that but doesn't appear to be working
It does
Ok, what if I wanted to find the number of combinations which satisfy what is being asked?
4 seeds? did you mean suits?
How would I go about that?
Idk how its called in English, but its the 4 common types
yeah suits
the number of hands with all cards having distinct values is 10C5 * 4^5
divide that by 40C5 to get your probability
Why 4^5?
10C5 = number of ways to choose which 5 ranks you get
and 4 ways to choose the suit for each rank
,w (10C5 * 4^5)/(40C5)
Xd
,w (C(10,5) * 4^5)/C(40,5)
there we go
I see thanks
Yeah yeah I was just thinking in terms of combinations
Thanks a lot both of you
can someone explain to me what a norm of a vector is in english, i look it up and have no clue what it means still
It is kinda its length
ok? wdym kinda
A length means that you have a notion of distance which is not unique in all context
but it is a way to understand it
so whats the difference between a norm and its magnitude then
wouldnt that be the same
If I have to go from point a to b I can represent a vector that goes from a to b and its norm would give me the distance between the points
would finding its absolute value i.e its magnitude be the same
except 'magnitude' typically refers only to euclidean norm
huh
while 'norm' can be more general
there are ways of assigning a length to every vector in your space that aren't the same as the euclidean norm you're used to but which are still consistent
there are certain rules an assignment of lengths must obey in order to be called a norm
so to find the norm id do the sqrt of ux^2+uy^2+uz^2?
"the norm" requires context
the question has no context
can you show the question
maybe it's a devil-in-the-details thing
as it so commonly is with math
That is the Euclidian norm
If u = (−1, 2, 2) is a vector in R3
, find the following:
a) ||u || (the norm of u)
well it wouldnt send the symbol
but thats legit it
okay
so they probably want the euclidean norm
since it sounds like youre not quite at the level where you would give 'exotic' norms any consideration
yes
yes
math complicated, thanks my guys
but at a higher lever you should be more specific
in math sometimes it makes sense to measure distance in ways other than the euclidean norm
isnt that the same thing tho
Yeah there is some distance that are easier to deal with depending on the context

Other than Euclidean norms?
What can be the other ways?
In algebraic forms or smth?
ok this is all going way over my head
i slept through every class so idk whats going on
@true crystal sorry for pinging but like I would really want to know what is meant by what Ann said
Some examples that is
There are a lot of other vectorial spaces than Euclidian space
Which one
This one
Probably vector space
Here is another notion of norm :
$||f||=\sqrt{\int_0^1 f^2(x)dx}$
Yes
sorry this is beyond me
You are like really quick I was going to change it xD
Guess this isn't for me
King1219
Why didn't you ping Ann then ?
Because
I am afraid
Is there some quick way of finding this?
For three degree things I would just check it manually but for 4 I just checked whether the things in the options make the thing 0
Yes. You can either plug in each pair and see if it produces zero or you can divide the polynomial by (x - (-1))(x - 2) and factor it.
Factor the remainder?
You need to be careful of multiplicities, though.
If they're zeroes, there will be no remainder.
Yeah that's why quotient
(x - zero) evenly divides a polynomial.
There will be a real number x that produces a higher value when filled into that polynomial than other reals.
Just put it as 1
Cause for any other thing
Or 2 actualy
But for any other thing it becomes minus
2 is small too
One returns 12
Bro
Why didn't I think of this
Ok now this is the one I couldn't solve after 15 minutes
Ugh
Shouldn't I put the value as 2
And then find the root of one equation or something
Lemme try
No
Doesn't make sense
Probably divide the 2 expressions
No still I will have 2 things remainder and quotient
Ugh
One must be (x - 2)(x - m) and the other must be (x - 2)(x - n).
If (x - 2) is a factor of x^2 + ax + b what does that mean ?
This
For some m and n.
I know that but I don't know how to proceed after it
Yeah is means that 2 is a root
OK, so expand the two things.
Expand (x - 2)(x - m). Expand (x - 2)(x - n).
Ok
Try to subtract the second and the first
I actually did that
then for x = 2 you get something
Did you expand the two?
No substracted both the things
I get 2
And that is correct

Today I learnt so much about polynomials
It's confusing how did I do that
That's not always correct.
I know I can expand stuff
For example, a = c and b = d is possible, which gives you 0/0.

We are probably assuming they are different.
You shouldn't.
Well, as demonstrated, the key is wrong.
x-2 is a common factor
x - 2 is also a common factor when the polynomials are identical.
Well, it might not be the only common factor.
Right, so there are multiple answers.
As demonstrated you are wrong
OK, well good luck.
"The answer key says you're wrong" is a very good bit of reasoning.
Answer keys are always right.
You said answer key was wrong because c = d was possible
But it also might be that c != d
That basically means multiple answers (0 and 2)
And that was just me meming
Sory
hi, I need help- figured out dzya and dxda, but unsure about dyda. based on the graph, 1) there's no cross section on the xz plane I can use to find xz bounds and 2) there aren't 2 y surfaces for the y bounds. one of them is literally a line??
how do i determine if vectors are coplanar, also what does coplanar mean
coplanar mean they share a plane
so any set of 2 R3 vectors will be coplanar since you need 2 vectors to span to get a plane
$X^2 - Y^2 = 4P$ where $X,Y,P \in \mathbb{Z}$ has a solution $X = P-1$ and $Y = P+1$. Is there a way to find the smallest solution X,Y?
Rahakasvi
is this channel free now?
i have a small doubt bout a thing its pretty basic
11/4hrs is the value of time give to me on a question what its real value i should be putting
cause its value coming is 2.75hrs
so does that mean its value should be 2hrs 45minutes?
yea
does it make sense?
thankyou
np
not really
which part?
i just thought that 75 is 75% of the 3rd hour
it is 😄
its just confused because of the fact that a whole hour is 60 minutes
not 100 like youd intuitively expect it to be probably, with percent
its maybe easier to see like
75% = 3/4 = (1+1+1)/4
so three quarters of an hour, a quarter of an hour is 15 minutes
hope some of that makes sense 🤔
yeah
this is probably a good time to go back to thinking of it as pies/pizza or whatever is helpful with percentages since a clock is divided in the same way
yeah thankyou its clear now
Idk what’s the error
is it really just that 5 becoming a three
that seems so dumb
hhaha
,w 26=3(x+1)^2-1
Is it???
theres a sign error too
lol i didnt saw the question and i was like his maths was perfect there
,w 26 = 5(x+1)^2-1
can you tell me where are you doing it?
I didn’t think it was the 5
is it some kinda app where we will solve and it will tell us our result
theres some weirdness in this step
i thought you might be able to "eat" it with the plus or minus
but now im not sure
$x=-1\pm 3$
ye
There is no 5 though
there is a 5 in the prompt but i think its just a typo
Mosh
I think it’s the error
does anyone know how this can transform into an equation
Is this a correct way of doing it to
i dont think theres a correct way
unless your class is using something specific
the answer is correct
what even is this
like you want to write the repeating decimal?
You can change it into a fraction if it's a repeating decimal
But not an equation
could have skipped a few steps by using quadratic formula
if it's been taught to you
Can you explain why it’s suppose to be -1
@glossy forge its true but useless one
I have a quick question for anyone whos got time
specifically they sort of switched the sides which you can do but its a little confusing
but just do like
move the -1 to the opposite side and divide by 3 @glossy forge it will be easy
I have the value of ph but I dont know how to isolate the OH since this is my first time using log
jan Niku
then it will be so
(x+1)²=9
x+1= 3 x+1=-3
x=2 x=-4
You're formula is clearly wrong
isolate for log(H) then use definition of log
ok thanks
it is? the teacher gave me this
is OH a single variable or O * H
its a chem formula
yeah, pH is measure of hydrogen, not hydroxide
pH is with H3O+
anyway, the math is the same regardless
but it tells me that its also with OH
no
you arent wrong I also have your version of the formula
oh well that doesnt matter the math is what matters here
King is just pointing out an error in the question, however the math to isolate for whatever's in the log is the same
yes
yes
I dont know what definition of log is this is my first time
$a^b=c\iff \log_a(c)=b$
Mosh
definition of log is how logs are defined...
apparantly its some kind of equation which is derived after using godels numbering
can someone help
the rules are : in case of basic medium ph=14+log oh , in case of acidic medium ph=-log h30
in basic, the concentration of ho is 10 exponent 14+ph , in acidic the concentration oh h30 is 10 exponent -ph
Won't that be $\binom{9}{5}$
killBird
oh bruh lol
As we choose any 5 numbers and then order them in only the increasing way
have you drawn it?
i have to draw it?
well I'd hope you'd make a diagram if it isnt provided...
since it's clearly geometry
It's arbitrary. You can write B, A, and T on any three different vertexes.
@hallow flax No, a is the opposite side of A.
Ok, then my apologies, different from what we learn here in europe.
t is the opposite of T. b is the opposite of B.
could you draw it out for me? if possible
Makes sense, thanks!
Do you have any idea?
Fill in the values you know.
@celest anvil Sorry, channel is busy.
You have two angles of a triangle, so you can find out the third one.
Do you know how?
i add them together?
You can the sum of angles in a triangle is 180°
Correct.
It isn't a rectangle triangle, so you have two laws, you can use. Do you know which ones?
Sine Law and Cosine Law
Exactly! To find out sides, I suggest the law of sines. So you can just figure the remaining sides out, using the law of sines.
Do you know what the law of sines says?
my issue is
last year
i slept through the trig online class
so i actually have no idea or any background information about cosine law and sine law
the law of sines says: $\frac{sin(\alpha)}{a}=\frac{sin(\beta)}{b}=\frac{sin(\gamma)}{c}$
Sparender
Sparender
oh okook
Basically, what it says, is the sin of the angle opposite to a certain side / this certain side, equals the sin of an angle opposite to another certain side / that other certain side.
You get it?
What exactly do you mean, by "their all equal to eachother"?
Check the formulas the "TeXit" Bot sent, and check them with the sketch a sent.
Perhaps it makes sense then 🙂
you have your sketch infront of you, right?
yea
yeah
and A = 62°
yep
Now you have one part of the law of sines:
send that again.
I did not get to see it.
$\frac{35,2}{sin(62°)}=\frac{t}{sin(T)}$
Sparender
yeah
Does that make sense?
$\frac{35,2}{sin(62°)}=\frac{t}{sin(83)}$
Sparender
Ok, you have that. Do you know, how to proceed?
howw did u get 83
$\frac{35,2}{sin(62°)}=\frac{t}{sin(83°)}$
Sparender
Perfect, so, do you know, how to move on?
you just have to rearange that, to have t on one side, and then plug it into your calc, and then you got it
Look at this again: $\frac{35,2}{sin(62°)}=\frac{t}{sin(83°)}$
Sparender
how could you get rid of the sin(83) to have t on the right side, isolated?
you can just multiply by sin(83)
then you get: $\frac{35,2}{sin(62°)}*{sin(83°)}={t}$
Sparender
Wait, I have to plug that into my calc, one sec.
Almost, check your rounding again.
40, yes, or 39,6, or 39,57
40
depending on how precise of a result you need, that should be stated by your teacher.
Perfect, hope that solves your question 🙂
Perfect, pleased to hear!
Hey but i have a question
Yes 🙂
i have another question and its reversed
Send it.
Draw a little sketch
Ok
Then we can go through it together.
by the way you are an amazing tutor
Good, so, we now have a problem.
The law of sines, gives us two possible solutions for angles in triangles.
Do you know about the unit circle?
no i sadly dont
Ok, the problem is, for a set sin, cos value, there [in most cases!] are two possible solutions between 0 and 360°.
For the these solutions [considering our problem] will be between 0° and 180°, so in theory, both angles could be possible for a triangle.
So, we have to use the law of cosines, as this law will give us only one possible solution for triangles [sum of all angles 180°, thats why].
You get that?
Do you know anything about the law of cosines?
$a^2 = b^2 + c^2 - 2bc\cos(\alpha)$ and $b^2 = a^2 + c^2 - 2ac\cos(\beta)$ and $c^2 = b^2 + a^2 - 2ba\cos(\gamma)$
Sparender
these are the three which you should know, imo.
again, considering this triangle: https://cdn.discordapp.com/attachments/269573202018041856/868214658983682108/1200px-Triangle_-_angles_vertices_sides.svg.png
Oh
no i didnt know anything about the law of cosines
but
I see
i have no idea
a = b + c
You want Angle B, so, the pertinent one for you, would be the one starting with $b^2$
Sparender
Umm yea
Good, so we will use the following formula:
$b^2 = a^2 + c^2 - 2ac\cos(\beta)$
Sparender
oh
you now have your different values, given in the task. You can just plug them into this formula, and solve it.
Do you know how?
or better, what I mean
Try it out, and see if it works 🙂
b = 6, a = 5, c = 7
$b^2 = 36$
Sparender
$a^2 = 25$
Sparender
$c^2=49$
Sparender
Yes
Sparender
Yes, thats what we want to find out.
my calculator doesnt give me a answer
now you have to rearrange this equation again, so that "cos(B)" is isolated on one side, I would suggest.
What kind of a calculator do you have?
Does it have CAS?
try this: https://www.geogebra.org/calculator
However, I suggest you use a physical calculator, you also get to use it during examinations, etc.. to get a bit of extra practice in rearranging equations, etc. [if it isn't a CAS calculator] it won't harm for sure.
I would start off with the easy stuff.
25 +49, you can get to the right side, just by - 25 and - 49
then you have the following: $-38=-70*cos(B)$
Sparender
You get that?
What I did, is just basically I moved the 25 and 49 to the left, by simply subtracting, so [-25] and [-49], that gets rid of them on the right, and on the left it makes 36-25-49, and that equals to -38.
.
Then I simplyfied $-257$
Sparender
Sparender
With that, you are almost there!
How can you get cos(B) to be the only thing on the right?
Sparender
the - gets cancelled out, so you are left with:
Ohh
Sparender
and now, to get B, you take it arcus cos.
Perfect!
I hope, I could help 🙂 If you have more questions, just send them, I am happy to help 🙂
Thank you so much
You are welcome!
Did I plug this in right, or does only the first x needs to be substituted
What is the task?
0.5?
well, yes, 0,542, and what do you get for the angle then?
wht angle?
for B
So here, for a, you then have $y=3^2-3*3+2$
Sparender
You still have to apply arcus cosin
whattttttt
to get the cos/sin value for a angle you just use the stuff you are used to, probably.
Yes, sounds pretty much right, it should be 57,121°.
I suggest you not to round intermediate results, to get a precise result at the end.
you get that @glossy forge ?
ohh
What you do for this problem, is you insert 3 for every x in the equation of this quadratic function, then you simplify.
🙂
Ok, no problem. I should be around for at least another hour or so 🙂
Ok great
You didn’t answer my question
.
you have plug the x in for every x in the equation of this function.
You only did that, for the first one.
and on the left side of the equation, you don't have any x, so I suggest to leave something like f(3) or y there.
ok thank you

is this server dead
clearly not.. but this is a help channel
how are bases with different exponents like terms?
Can someone tell me if I plugged these in right or not
wdym? pretty sure they are not, which is the reason you cannot add or subtract them when simplifying
As far as I can see, I think the channel is in use, however, you should keep something like f(3)= on the left side.
Is the =(3) part of the equation or should I leave it out
Lets move to channel 3.
@alpine sable
It’s a yes or no question
in this expression somehow they do
here there is no adding or subtracting, so you'd have to use the exponent rule
so it doesnt matter if they have the same exponent in this case?
nope in most cases it only matters when adding and subtracting
here you can use the power of a fraction rule to make it look better
like this
Not sure if anyone has answered somewhere else, but differentiating sqrt(x) is the same as differentiating x^(1/2), and as you should see then a factor of 1/2 should pop out, which is where the 2 comes from
$\frac{(xy^2)^-2)}{(x^2y)^-2}
"nope" as in they dont matter right?
$\frac{(xy^2)^{-2}} {(x^2y)^{-2} }$
yes
Venti
it's my pleasure
if you need any more help then fire away
hmm could you show the full picture, I'm trying to figure it out but I'm as stuck as you at this point lol
im good now but ill hit up if need help with sum else tho
hopefully I'll be awake by then but there other wonderful helpers who are happy to help (I hope) if not
I having a feeling it's cuz x cannot = 0
no it doesn't
@meager lily it's because the derivative of u given by du/dx is 1/2*sqrt(x)
completely forgot how derivatives work for a minute there lol
yeah and then how does 1/a^12÷b^8 become 1 ÷ a^12 * b^8?
Dividing by fliping the b^8
So it becomes 1/a^12 × 1/b^8
Which is 1/a^12 b^8
U could also see the fraction as a^-12×(1/b^8)
Which would then be (1/a^12)×(1/b^8)
Which gives the same result
Division and multiplication are inverses of each other
yeah
So when u divide by b^8 thats the same as saying the reciprocal of b^8
Which is 1/b^8
Okay, I get it now. Thanks for the explanation 👍
Np
It's 1 am for me, so I might just be tired lol. Goodnight anyways
Goodnight
What im confused
not sure if im starting this off right..
i write it down as
$32=27e^{k(12)}$
oops
Reverie
Reverie
not sure what im doing wrong
Reverie
Yh
No
Its ln(5/7)/12
oh actually would it not be
Becuz when u natural log e^k(12)
1/12 ln(5/27)
its 0.014
oh so it's 32 not 5
Yes
ah got it
32/27
Vertex form would be $y = a(x-18)^2+12$
RipeOrange
We know at x = 0, y = 0
So plugging that in you get $0 = a(0-18)^2+12\implies a = \frac{-12}{18^2}$
RipeOrange
i see
Thank you
5=log(50 000P) i need to isolate P and i forget how to do
Just send in one channel...
Did I plug this in correctly
Law of cosines
Law of cosines
law of cosines
just plug and chug
Yep
ahh i see
Plug into the equation
I just learned about law of cosines and its so useful O_O
Now derive it
maybe if i learned 😭

whats derive? english is not my native language
Oh dw I did :))
Niceee
Deriving stuff is a lot of fun to me lol
wait
is the answer 18.71?
Is this right?

hey.. could someone tell me if im right
f(x) = 5x^2+3, they tell you that the output is 3
that means when you plug in the input, you get out 3
so 3 = 5x^2+3
and you solve for x
,w √(10^2 + 20^2 + 21020*cos(68))
damn it
Oh wait
is that the answer?
,w √(10^2 + 20^2 - 21020*cos(68))
Yea you're right
Ayee lesgo
Apparently I forgot the right formula oof
..............................
the direction of v
Well I’m not sure how to find it
angle from the positive x axis
Is it just slope
try drawing a triangle, with the positive x axis and the vector
then using trig to find the angle between them
So is it A?
yea
how'd you get 10.7?
sine law
10 sin 64 is 8.988
$\frac{\sin(64)}{\overline{BC}}=\frac{\sin(42)}{10}$
Mosh
I don’t think so
no
Well, what are we trying to find in the question?
ok thank you
length of the side BC
So from this equation can you solve for BC?
Isosceles doesn't mean that it's not obtuse or acute. It can be both. However I'm pretty sure that's not an isosceles triangle you got there anyway. @silk coral
It can be obtuse, or right, or acute, and also be isosceles, here's an example:
Which of those questions?
Do you remember the formula for the volume of a pyramid?
Hmm, read the question carefully
What does 'area base' mean? $A_{base}?$
ShurjoA
Is that the same as the house's base?
Yes
No problem!
yo i just finished calc ii but i left with some existential questions
what does it mean to calculate the cosine of pi/2 radians
or idk the cosine of 3pi/4
thanks
i got it right
ok how do u calculate the height when they give you the slant height and the radius
like what’s the formula
cosine is a function, that takes angle to number
if you draw the unit circle and place your angle counterclockwise from the x-axis, then the cosine is just the x-coordinate of the point found.
^
what radius?
can u use another channel
you mean cone?
uh nvm actually just go on
yeah notice the right angle triangle
yes
thanks
im remembering now
use that right angle triangle to calculate the height?
pythagorean
ok
thanks
i keep getting the wrong answer
for my question
idk why
never mind
the height is
12cm
someone halp
pls
Are u familiar with zeroes of a polynomial?
@alpine sable
wait sorry
this is 1
right
because -6 and -3
Ye
but idk how u solve for a polynomial function
also I need help with dis
Well u gotta look for the points in which y=0
So you can analyse the function
why y=0?
owo
so like both x values hav eto equal 0?
Oh no i mean
Give me a second
oo oki
Bru discord is taking ages to open in my PC
yeah alternatively you can sketch f(x) for various k
Anyways
Yea u can plug different x and see what graph has those points
But
oh and btw im speaking of the 1st question about graphs
ohhh
yeah I got 1 because I did -6 and -3
idk why they work tho lmao
That would take too long
I really ned to finish alg 1 by the end of the month
or else I wont be able to transfe rto a new hs
if the product of a polynomial is 0, one of the factors has to be 0, right?
you got this!
are all products of polynomials 0
ok so, analyzing the zeroes of the graph of a function can be useful since we know that if y=0 it means that one of the factors is 0
so you gotta find what x's makes the function have a 0
in this case
x + 6 = 0
ye so -6
and -3
but idk why it works TBH
alr if we have a polynomial that equals 0
wait

