#help-0
1 messages · Page 859 of 1
Now substitute A, B, and C into here
which will replace the fraction in this integral
I dint understand this part
if (x+iy)^((1)/(3)) =a+ib then what is (x/a) + (y/b)
oh hold on
Nvm I can't do both I'm stupid
Or I can take log |1-x|/-1
On right
So I should vg t
-1/3× -log |1-x|
Which is
1/3log |1-x|
Hi everyone, I am creating a wallpaper for my pc but I have encountered the following problem:
My pc has a screen with an aspect ratio of 16: 9 and I want to insert the album covers without having to cut them, so with the same dimensions as height and length
what is the minimum number of covers I can put vertically and horizontally to fill the screen?
Ok thx alot
yes this is right but don't forget the + C
um
i guess at the end once you're done
how do i get the derivative of a function i dont know😭
Yea
Which function?
do you need to plug things in or nah
what is riemann sum?
can this also be written as x=-2 ; x=8
like i know what the definition is
but how is it different from simply finding the integral?
and when is it used in place of simple integration?
just use this
riemann sums are an approximation of an integral when your step size is small
with a step size approaching infinity, it is an integral
why dont we take the last point
when calculating the riemann sum?
depends on which riemann sum you want to use
yeah i am talking about LRAM
why do we leave the last one out?
no
just because its an approximation starting from the left
i mean
excluding the right most point is like purposefully making it inaccurate
because you're leaving a section out from the area under the graph (between the end points)
basically, different graphs work best with different approximations, which is why 5 different types of approximations exist
this is mostly because the left Riemann sum amounts to an overestimation if f is decreasing on this interval, and an underestimation if it is increasing
LRAM (and RRAM) also provide a practical way to calculate the integral
this is also useful in multivariable calculus when proving integrals in 3D
i still don't understand how it is valid to leave one of the sections out
its just so there are multiple ways to approximate an integral
Hi yall, I was solving a logarithm question and I got something like this (actually a equals to log 2 and all of theese in a big square root, but I only need to remember how to solve theese type of exponential numbers)
im so lost
Didn't you asked the same thing on #help-1 ?
the person wasn't sure of their answer?
so do you know?
If theese parentheses are same with [ ], the answer is -2 ≤ x ≤ 8.
But if it is ( ), it is -2 < x < 8
I've never seen such a parenthes like this, maybe because of I'm not american idk.
if it is { }, the answer is x=-2,** x=8**
First of all, a is greater than 0
Because of a^(-2) = 1/a², so you may let t = a² (t >0), then a² + a^(-2) = t + 1/t
Assuming that t + 1/t = k (k > 0)
⟹ (t² + 1)/t = k
⟹ t² - kt + 1 = 0
Then you just solve this quadratic equation (remember to eliminate negative roots of the equation)
*Sorry if I made mistakes
I can solve rest of the question now, thanks!
so this is incorrect?
is this correct?
please ping me
Not quite
You are saying that, given a product AB, then AB is less than 0 if A<0 and B<0
But if A and B are negative, then their product is positive
For AB<0 you get two cases:
Case 1: A<0 and B>0 or
Case 2: A>0 and B<0
@heady tusk
so there is 4 answers?
ok
However there are 2 cases, each giving you one interval, and the union of those 2 intervals is the answer
You don't usually solve quadratic inequalities this way
You graph the parabola with the x-intercepts and see where it is above and below 0, those intervals are the answers
,w graph (x-8)(x+2)=0
From this graph, can you see for which interval of x, the quadratic is less than 0?
Np
Yes
,w graph (2x+1)(x-3)(x-3)
You might also see it written as $x \in (-2, 8)$
.itsjustnai
k thanks
$(2x+1)(x-3)(x-3)=(2x+1)(x-3)^2$
.itsjustnai
(x-3)^2 is positive for any x
oh yes
So you want to find for which x is (2x+1) also positive
so it's x=3
x=3 is the x-intercept
yes
You want (2x+1)(x-3)^2>0?
and - 1/2
yup
Right
wait lemme try
Alright
If AB || DC
so DF || DE?
@feral zodiac this channel is occupied, move to a free one
Okay, do you help me in #help-4 ?
A is positive for x>-1/3, B is positive for every x except 3
what is A and B?
A: (2x+1)
B: (x-3)^2
-1/2 you mean?
so its
We dont check when both of them are negative because (x-3)^2 cant ever be negative
,w graph (-x^2-1)(x-1)
@jade birch (-x^2-1) will always be negative right?
Yes
can't x be anything?
because it will always be multiplied with a negative
making it lower than zero?
@jade birch
No
because the other bracket has to eb a negative
so
positive I meant
it has to be a postive
because + x -
= -
so x always has to be higher than 1
@jade birch
am I correct
The left is always negative
To get a positive result, the right term has to also be negative
To get a negative result, the right term has to be positive
so I'm correct
nice
so like
my notes only give a method where there is 2 terms on the right
for ex
8 + 2i
but now there's only 5?
@jade birch
So you have a complex number on the left with Re(a-2b) and Im(2a+b)
But you also have a complex number on the right with Re(5) and Im(0)
Two complex numbers are equal if their real and imaginary parts are equal
So you want a-2b=5 and 2a+b=0
I think I did that right?
Looks correct to me
Yep
how to plot this in gnuplot?
Yes i^2 = -1
(2-i)^2
Because it treats i as a variable, not as the imaginary unit, I guess
is 3-4i?
Yes
how do I make a calculation with this bot
,w (2-i)^2
You send a query to wolfram
,w (3-4i)(2-3i)
Why did you ask me this?
Nah, just high school maths
I want the normal form
Why 3^x<=-5 has No Solution?
a^x, if a is positive is always positive, therefore 3^x cant ever be negative
It is an exponential equation
Ahh yes. Thanks
What about if a is negative?
Well, for starters that is not an exponential function
And also it jumps into the complex numbers, if you had (-2)^(1/2), that would be isqrt(2)
i have to calculate the quadratic eqaution
if one of the roots is x=3+7i
@quaint trout does it still look correct
You are just expanding (x-(3-7i))(x-3-(3+7i))
So, (x-(3-7i))(x-3-(3+7i)) = ... = x^2 - 6x + 58
You are simplifying an expression, there is no equation
OK thansk
@quaint trout
I hav e5o write this in poalr form
but do I use - 1?
or 1
Do you mind if I ask where you are from?
when calculating tan
South Africa
Cool
alright
But use radians 
we're not doing that yet
we will later
It is known that the covariance of the variable X with Y is −143.8, with G 4 and with K 487.8. In addition, it is known that the standard deviation of X is 4.4. What is the covariance of X with a variable D defined by the formula D = 143K + 2.8G + 2X? Does anyone know what I should do with this task? 😄
on the 3rd line move the 1 to the other side to form a quadratic in terms of cosx
^
If you have trouble seeing it, let y = cos(x) then you have 1 = 2y^2 + y.
So solve for y
but then remember to convert the y back to cosx once you find the solutions
Thanks
Why can't this be evaluated using the power rule for integration and then dividing by the derivative of the function under the square root?
Because the 6-x^2 is not a linear function
That rule only works if the inner function is linear
You'd need a trig sub, however it's easier to just draw the graph then interpret as signed area
oh
damn
ok ty
and can anyone help me with the last 2 questions
i dont know what im supposed to do whatsoever
what is 196883+1
do it yourself
ok
second:
if you take the inner isoceles triangle you have one angle (56°) and one side 18cm, half it for 28°, 9cm and right angle -> rest you can work out
third:
bisector means it's half
so 30° and 28cm, find half the opposing side
wth am i doing wrong here? I had to find the perimeter. I divided the quadrilateral into 2 triangles one scalene and one right angled. I used the cosine rule on the scalene triangle to find the hypotenuse of the right angled triangle which I called B. I used Pythagoras to find the value of g by doing B^2 – 5^2 which gave me 304.39... which I added to 14,5,9 to get the perimeter. the real anwser is 45.4 btw to 1 decimal place
idk
what does the sentence "the ratio of fossils to artifacts is 2:9" means to you?
I think it means for every 9 artifacts, there are two fossils?
how'd you get to a?
dont give answers
then, what if there were 90 artifacts, how many fossiles ?
so yes this is correct
20 fossils
so i divided 279 by 31
The idea is, find how many groups of 9 artifacts are in the 279
ah alright
the point is to help understand, just to give the answers
you're still giving the answer
no
im trying to explain
if you're not going to help, dont type
You wait buddy
so when I divided 279/9 its equal to 31 so in the original ratio it would be fossils to 31 artifacts
and now I just need to find the amount of fossils
Well no, the ratio is still 2:9
The 31 is like the number of “groups of 2 artifacts and 9 fossils you have”
the way got 20 earlier with what i asked is because you naturally got that 90 is 10 times 9, so you calculated 10 times 2 and you found the number of fossiles
how would you find the zeros algebraically?
in use, and dont ping helpers instantly
now, you know that 279 is 31 times 9, so what calculation would you have to make to find the number of fossiles?
oh sorry
so you multiplied 9 times 31 groups to get 279 total artifacts
so I would need to multiply 2 * 31
to get 62
i get it now thanks
well done
you can already factorize by x, then set X=x² and see what it becomes 😉
Anyone know surds? A bit advanced
completed every question apart from the last 2
what's the question there? simplifying the fractions ?
Have you heard of rationalizing denominators?
Of course that’s the method.
do you remember how to?
What methods are you thinking of
multiply by the denominator with a different sign
alright you’re on the right track
If you’re getting lightheaded solving math, try taking a break for a while and coming back to it later refreshed
I have and I’m back now
ah
You need both of them?
just stuck in the last 2 yeah
For the fist one keep the bottom as one function
So you would just need to times by:
(root 2 / 2 ) - 1
on the top or on the bottom?
like let’s say to begin
I have to multiple by the denominator right
different sign this case subtraction
How should the top and bottom be
How should the numerator and denominator arrive
So just expand it
more efficient way $=\frac{\sqrt{2}}{1+\sqrt{2}}$ then rationalize
Mosh
Alright gimme a sec
Being used sorry
What?
Need to move to different channel since this one is in use
I think I got it
What did your answer arrive to @north needle
Show me your expanding working
I need to compare and contract
How can i delete this message
Gis a sec
YES MY GUY
top class
There we go
My working agreed with yours and I just checked the answer
perfect
how do I find the work done by gravity to a satellite in orbit
can u solve these
@alpine sable
Simple
I’m also in the same topic
for a) do this
5 is already done so what is 5 the root of?
25
25x3 = 75
- = square root of 75
Do you get it?
let’s go to no. 2
No worries always get back on track
ty
Hi, Mr/Ms.MilkyWare
My proposal for you is to draw triangle first
Did you ?
is this channel taken?
I don’t get how question ii is worked out here
Cause I did not solve it like this so I’m abit confused
What's confusing you?
You don't have to take the derivative, and even if you did, did you get that the function is minimum at the same point?
yes i got same answer
The amplitude here doesn't matter. We need to find when h is lowest.
We know that -1 <= sin(theta) <= 1 right?
Since we want to minimize the function, we put (-1) in place, as the smallest value
that, multiplied with 0.7 which is the amplitude, gives the minima
ohhh
so is it cause amplitude wont change the points of the maximum and minimum
originally i thought you have to take first derivative and equate to 0 to find maxmum and minimum
can anyone help me solve this pls
The length of the amplitude doesn't change where the minima and maxima are
I seee
thanks for the clarity
Usually yes, you do. However the sine function is periodic and its properties are very simple. Therefore we can just plug in -1 for it
No problem ||also it isn't a shortcut, we know when sine is minimized by the inequality above, therefore the minima has to be reached somewhere||
peacgiant can u help me
where is the question from? @digital needle
a test my instructor gave me
a practice one
The total perimeter before gluing is 19*3
What sides should you glue to remove the least amount of perimeter?
Haha definitely felt like a mathcounts question
u mean gluing right?
Right
hmm
okay i understand this
i dont this
If I glue two sides together, those 2 sides stop being perimeter
Yea
So with 2 triangles you can choose either the 5 or the 7
Which is best to go for the greatest perimeter?
7?
Nah, because that would subtract 7*2 from the perimeter
Now, what can you glue with those 2 triangles and an extra one?
Might have to draw it
for the the two triangles when glued together do they make a rhombus shape?
I think so, not sure on what sides are parallel
the base
is it what or where?
Like what length sides cane be glued now
well, if the shape is a rhombus we can glue the side with a 7
to any of the existing sides with a length of 7
why is it true that $n!=\int_0^\infty e^{-t} t^n dt$
@digital needle is the answer 33?
thats what i got
TheToadSage
repeated IBP
or differentiating under the integral sign, which a professor from Oxford has done a video on the exact problem
i dont get how to do it by IBP
Richard Feynman famously used differentiation under the integral sign to solve many difficult problems, including one during his time at Los Alamos Laboratory during World War II that had stumped researchers for 3 months.
Learn how Feynman's Integral Technique works from Oxford Mathematician Dr Tom Crawford with the help of Ben Orlin from Math ...
you just do IBP n times
$\left | \left (\frac{n+1}{n} \right ) ^n - e \right | < \epsilon$
Danajax
No
why not?
the stuff inside the abs value isnt necessarily positive
so how should i proceed on that inequality then?
yes,
One dumb question, x-2 is the same as 2-x?
no
proove it yourself $x-2 \not = 2-x$
Danajax
bc I thought that -x is the same as -1*x, so I could take the -1 and multiply it by the 2
lmao
think that x is a variable
any number
so easy number 100
test with 100
take x=2
oh I see
xDDDD
that was fast
lol it wasn't for you
nopr
hax
Can someone explain me how did this happened?
hi guys
how is this possible
i keep getting different results and he got 0.947241
i have no idea how though
h=4.8 btw
so tg(4.8*1.804219591) is supposed to equal 0.947241
or should 4.8*1.804219591 i tried to times 180/pi but still no result
any idea about this? 😦
same goes for here
how in living hell does he calculate that tg and cos is beyond me
R=5,h=4,8 though
though it is: cosh1.804219591
oh my god...
it's cosh (x) function
and tanh (x) function
i can't believe this 😄
does anyone know how im supposed to find this base
am i supposed to end up with a quadratic formula?
I know this is a stupid simple questions, but i wanted to double check. If i had .003% of people out of 15,510 people. That would be 46 people? Because it would be 15510 * .003% = 46 people
yes
thank you!
@minor solarwait
Can u help
was that % actually 0.3%?
if u want 1%, then that is 1/100 = 0.01
if u have 0.003% then that is 0.003/100
so 15510*(0.003/100)
=0.4653
so its .46 people?
(illogical since it can't be half a human?)
maybe they have converted original 0.3% into 0.003 already ready for u to calculate i don't know
so that statstic would make it half a human>
you need to ask
im calculating dick size lmao. trying to figure out how many people have 9 inches and above
so that means .46 people will have dicks biggetr than 9 inches
that's rare
significant research i must say...
wow, so even less than 46 people
no u're not
well it is rare
because it's irrelevant to have bigger than average
more than that it is just weight in life
nothing more
and if u think ladies are impressed with such a thing, no they are not
only the sluts
and you want to avoid them really, because they are not a keeper ey?
xD
help me
wise words
you can calculate this in wolfram alppha man @tidal lion
-0.25
7x+5y=331
4x+9y=398
i got 7X+5Y=331 and 4X+ 9Y=398
yeah i did that
but how to answer that
is it by elimination
7x+5y=331 / 5
both are the same
oh
also u can use system of linear equations
just divide both sides that convenient
@sharp sablein that second equation u have 4x+9y=398
so u will now have when u transfer that y u got in first equation
yeah
4x+9(331/5-1.4x)=398
yes
u get X and then u put that value X in first equation 😄 and u get Y
u can use matrices as well
no probs mate
how i solved this was:
I found a factor for the large buses (5 and 9)(i should have done 45, the least common factor), 90.
Then I wrote
(7s+5l=331)*-18
I got 18 from 90 divided by 5.
(4s + 9l=398)*10
I got 10 from 90 divided by 10.
Then I multiplied them and got
-126s + 90l = 5958
-40s + 90l = 3980
I subtracted them and got
-86s + 0 = 1978
Divided 1978 by 86 and I got how many people the small buses can carry.
Then to get how many people the large buses can carry,
I did 331 - 7s divided by 5.
There's another way to do it if you want.
damm
that's pretty good too
thanks
uh is this occupied
hi
no
ah good
i don't think so
for this question lol its easy once u can come up w the graph but i cant
hi
is there a way to solve this using calculus idk
;-;
uh
bro im so lost
to see if someone knows how to help me ?
which level math u guys doing
SURE
bro
my question must be a easy leve one
It definitely has 3 POI
Oh wait does it have 4 POI
<@&286206848099549185> I have this graphing question
So on this graph on the very left would you consider the stretch at -5 a POI
can i use the channel
I’m trying to understand what it means for a functor to be full. If f wasn’t mapped to F(f), that would mean that not all morphisms of the domain or mapped to the morphisms of the codomain, therefore the functor is still a functor but no longer full right? Sorry if this question sounds stupid but I’m still new to functors.
wait
do tehy help for algebra
here
9th grade math
i in 7th grade and doing 9th grade
math
Can you please show your work?
huh?!
what is your first step?
is this a given?
As I understand, shouldn't it be $(a^{2}+2abi-b^{2})^{2}$?
oh, i see
is asin(x)+bsin(x) equal to (a+b)sin(x)?
f has to be mapped to something in order for F to be a functor, so not mapping f to anything is not an option
Since there's only one arrow in D between F(X) and F(Y), there's really no choice in the matter except to map f to that arrow
Guys the spectrum of A is the set of proper values right ?
Yes
I sorted it out using desmos but thanks for confirmation
yes
oh ok thanks
to get 1-cos^2x they used the Pythagorean identity
sin^2 (x) + cos^2 (x) = 1
sin^2 (x) = 1 - cos^2 (x)
yep! in fact, many of the identities are found through this main identity
for instance:
is derived from that identity, and you can see that by dividing all three components by cos^2 (x)
or
which is derived the same way, but by dividing all three components by sin^2 (x)
hi need help
no worries!
question: Find the smallest value of N, for which S∞ − SN < 0.5
not sure where i went wrong tbh but the answer seems so wrong
what's the sequence
anyway your second step doesn't seem to make any sense... how did you divide 160 by 0.5?
you should have subtracted it just guessing based on your operations here
lol idk what i did
whats wrong with me
i dont know what to do
i know i need to use logs thats it
What should I do
If (x+yi) = re^theta(i)
Does -(x+yi) = -re^theta(i) for
yes
omg i know where i went wrong
thanks anyways
i should have used the equasion
20/1-7/6 = 160
so i can cancel them out
just draw a seperate diagram for A and B then for B and C then C AND C AND D if ur confused
but its the same concept i dont get you
HCF OF 450 AND 180 AND HOW DID U GET 90? HELP
u not gonna sleep huh
how do i solve for 0 on this
i swaer im dumb or something
iset = to 0
can i u multiply the demonimator/
?
i jsut do lnx=1?
isnt ln 0=1
ln 0 = 1-1 = 0
the answer isnt e either
kinda dont know what to do from here
What seems to be the problem?
i have no clue how to dolve for -
0
my algebra is kinda weak dont know how to get started
i mean i can umltiply entire thing by e right ?
You mean when x = 0?
solve g'(x)=0
Oh ok
when that equation = 0
Gotcha
its quotient rule
(vu'-uv')/v^2
^
to solve for when it = 0?
yeah
what
get the derivative and set it = 0
ok let me say again
im trying to sovle for when the derivitvve = 0
and i kidna dont know how
here is the q
instead of just e like u type
__--
d
well here how do you even get that from the derivitve
cuz what i did is multiply the bottom
I think e isn't an acceptable input in whatever site this is
to both sides
that's right
2nd place
$e\approx 2.72$
2 decimal places
tens hunddrehs
Mosh
Lol wait until you join engineering school
Quick question would inc be (-oo, -2] [2,7]
Dec(-1, 2]
iirc if its closed point then its included
yea looks right to me
im doing implicit differentiation. is the derivative of 2y = 2 or = 2y(dy/dx)?
it's 2(dy/dx)
Hi can anyone help me with this problem pls
you have k aces b/w them
that means that the max is 2 aces per hand
4 aces in 1 hand and 0 in the other is 4 aces b/w them
oooh okay
tbh i dont even know how to approach this
halp
theres like 6X10^12 or something like that different combinations for hands you can get but I cant figure out how to get all the ones w/ aces
you have a 2/26 chance of getting 4 aces out of the deck
3/52 chance of getting 3 aces
1/26 chance of 2
A AND G and J can some one please do them as an example
@somber moat can u pls help
these are pretty common squares, the first on is 8. remember that sqrt(ab)=sqrt(a)*sqrt(b) to break them down into easier square roots
so for (g) 441=49*9
and for (j) 900=9*100
^them there factors can be easily broke down
would you be able to help me pls?
how big are bridge hands?
so you need P(k aces in 26 cards)
Pretty sure permutations is better here
P(a)=mod(a)/mod(capital omega)
how so?
how was the range found out here?
Sub x = 1 into equation
but why specifically 1?
Because that’s the lowest value x can be
Otherwise you’ll get a negative square root
So to get lowest value of y
ok 👌 thx
Orient yourself around point C, it is the only one that doesn't move. Also notice that C is on the y-axis. Points A and B lie on the same horizontal line (they have the same y coordinate) and the distance between A and B to the y-axis is the same.
If you can't imagine the triangles formbed by f), give some values to coordinates a and b and see what you get
so just find values for a and b and put it into a distance formuila?
how would we do this with the formula
Ohh right
And you're finding the distance of all 3 sides and then the type of triangle?
yes
Lemme try writing it out
ty
Ok so you get that AC=BC
Just plug the coordinates in the formula
yes
You don't get anything nice
and what do u get?
except for AB
how do u know there equal??
Well because they have the same equation?
Send a picture if you want
np
@jade birch would it be isoceles then?
The triangle will always be isosceles, yes. That is because AC = BC.
As a bonus, you might want to try and figure out, which condition should we have for a and b so that the triangle is equilateral.
Yes, that is precisely what we get for the equilateral case
how would we figure it out'
So what we know for certain is that AC = BC, that is true always (by using the distance formula)
Now we try and see when does AC = AB
Can you calculate the distances and write the equation?
Hmm, some terms are missing, and the square root is missing
Did you mean 2a = sqrt(a^2 + b^2 - 4b + 4)?
Alright, we can square this equality, what do we get?
Try to simplify as much as possible
4a^2=a^2+b^2-4b+4?
Yes, I'll move all a terms to the left
We will be left with 3a^2 = b^2 -4b +4
This is also 3a^2 = (b-2)^2
Alright, let's take the square root of both sides
did u minhus a from both sides here?
(this is also where we introduce the plus minus sign, since we need to do that when square rooting)
I did yes
ok so wat does that sign mean?
When we square root something, for example sqrt(x^2) isn't just x. I won't get into the whole thing but in equations you can also write plus minus x
It comes from the absolute value, but we needn't talk about that
So taking the square root of this equation yields +- sqrt(3) a = b-2
Why would we need to square root -4?
as in taht
We don't take the square root of individual terms, we take the sqrt of the whole expression
So we took the square root of b^2 -4b +4
which is the same as the sqrt of (b-2)^2
Are we good so far?
kind of
Ask me anything that bothers you
OH
wait
i get it
b^2-4b+4 is in the format of that thing where u square a term
so we ignore the middle term?
these two things are the same
Np
Hello I've got a question regarding a normal distribution example with μ = 35 and δ = 2
and have to find out the ? from the statement below:
P(X <= ?) = 0.2
The answer for the example is given to me but I have no clue what formula I have to use to reach the result.
Result for ? = 33.316
what is your understanding of domain?
The domain of a function is the set of its possible inputs