#help-0
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the subject was related to pendulums, and harmonic waves.
sorry if this is not the correct way to ask for help for an issue like this.
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Can i get some gelp for this question
Theres another way to solve this equation but i forgot
I think if you have 100% of liquid with 15% of milk, so 85% will be a coffee. Next do the math.
How
Yeah thats what I got from my other equation
What would be the equation for it though
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That's just the choice of coordinates. The middle of the rod is the origin
l is the length, so l/2 is half the length in each direction
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im like raging rn this is really confusing
a teacher decided to have pupils work in groups today. She put them in groups of 4 and had 3 groups work on activity A and the 7 remaining groups work on activity B. How many pupils are there ?
Is it easier that way ?
can you tell me how many groups there are ?
and if so, can you use that to find how many students there are ?
@glacial jasper Has your question been resolved?
whatever you do to one side of the equality, you also have to do it to the other
e.g. we want to isolate x right?
we can first add 3 to both sides to get rid of the -3
but we also do it to the right
so we have x/4 = 10
then we multiply by 4 since we want to get rid of the /4
we also do it to the right, so we get x = 40
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Howdy, Im trying to find the cartesian inequation
Im stuck after converting z to x+iy form ;/
Hmm...
Ok so the Re operator will basically remove all the imaginary components of the z.
It only gets the real parts.
Oh, thats what that is for, never seen that 
So when you multiply z with the parentheses, you get 9z + 5iz.
And Re(9z + 5iz + 1) = 9z + 1
And you can then continue your inequality
where does the 9z come on the otherside?
From distributing the z into (9+5i)
im talking about the RHS
No that's just applying the properties of the Real operator
Hmmm okay
The inequality turns from
$$\Re( (9+5i)z + 1) \le 0$$
$$ 9z + 1 \le 0$$
Ausaramun
Okay but I cant solve that for x can I?
But, $$\Re((9 + 5i)z + 1) = \Re((9 + 5i)(\Re(z) + i\Im(z)) + 1) = 9\Re(z) - 5\Im(z) + 1$$
pi over four
Guess I need to divide it into lines, it can’t display the whole equation
But, $$\begin{array}{rcl}\Re((9 + 5i)z + 1) &=& \Re((9 + 5i)(\Re(z) + i\Im(z)) + 1)\ &=& 9\Re(z) - 5\Im(z) + 1\end{array}$$
pi over four
Oh yea I forgot to account for the imaginary part of z
so how do I find the cartesian inequation?
I did the conversion part, now just note that if $z = x + iy$ (where $x$ and $y$ are real numbers), then $\Re(z) = x$ and $\Im(z) = y$. Replace $\Re(z)$ and $\Im(z)$ in the inequation I got, and you will have the answer.
pi over four
but that would only leave 9x-5y + 1 right? I wouldnt be able to solve explicitly for x?
I've done other region questions with imaginary numbers and usually solve for x
Yes
This is because the inequation represents a region on the Argand diagram
So you can’t really solve for x or y
@dusky basalt Has your question been resolved?
Sorry its not correct
that inequation represents the region
how do I find the cartesian equation
But you can’t convert an inequality to an equation
cartesian inequation*
It really does look like a region above a straight line though
That’s $9x – 5y + 1 = 0$. But if you want the region it’s $9x – 5y + 1 \leq 0$
pi over four
Ok yeah I understand
Thankyou for your help @lofty oriole
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A sorceress has summoned a spirit and has contained it using a perfect 10 ft wide circle of salt on the floor of a rectangular room (the circle of salt is centered in the middle of the room). The sorceress stands in the north east corner of the room. The north wall is 15 ft away from the salt circle, and the sorceress is 30 ft away from the spirit when it appears in the center of the circle. What are the dimensions of the room?
I need help finding the equation
draw a picture
goofy ahh question 💀
I mean
The sorceress could be in any diagonal from the center
It just depends on how long the East-west walls are
Lol would it be 50 x 10sqrt(11) ?
I mean
If we assume that the sorceress is in the corner
But like
The sorceress could be anywhere
She could be above the circle
Let's assume she can't fly ye
k
wait howd you get that?
Lame ass sorceress
Rest is obvious
Np
Anyone know how to get this? 🤔 intially I thought that all you have to do is divide the number then add 1002 but that is incorrect
"In a municipal election 39218 votes were cast for two candidates. The winner had 1002
votes more than the loser. How many votes did the winner receive?"
19104
you sure? I was attempting it again and I think the winner gets 20110 votes
pythagerous right?
Yes
x=sqrt(275) in the diagram I sent
Bro I think you should study pythagoras theorem again
lmao
pls just tell
Here x=sqrt(275) and the length of side of rectangle is 2x
ohh i understand
and then the height is 50
thx
Yes
Yes
alr thx
@dusky elk Has your question been resolved?
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Uh I got a question, so like how do I know the length of something from the perspective? Like I'm standing awy from something it appears to me to be 5cm but in reality it's like 10 so how do I found out it's 10? Is there a type of rule or what
Yes but the thing is
I'm trying to find the real side yk?
The angular size I'm seeing I got it and I got the distance so what do I do to get the real size?
@umbral dune
So I multiply?
?
Ight so I multiply angular size with the distance right?
But den it might like give me a big number lol
Hmm can you give an example cuz I'm a little stupid?
Hmm well I'm trying to do it irl yk? But I don't have the numbers right now
But let's say
I see something the size of 5cm
At a 100cm distance ok?
How do I get it's real size yk?
Cuz if we do 5x100 it would be 500
Which is too big yk
So do I still divide it?
No I'm giving an example the size I'm seeing is 5cm yk?
I'm standing away from it
And it appears to me 5cm
So look ill tell you the irl thing I'm using this for
So look something behind a glass
And I'm trying to find it's size yk?
So let's say I measure its size from the glass yk?like put a ruler or somin like that on it behind the glass
And let's say it gives me 5cm yk?
And there is like a 30cm distance
So how do i get the actual size? 💀
Well like I think it don't really matter since its like yk I'm measuring it from the glass yk?
It appears on the glass 5cm on the ruler
And like a 30cm distance whats the rule?
Hmmm
So like I put my eyes a little far from the glass right?
And then see how tall it is
Then what
@umbral dune
Then what 💀
Ik. What I'm saying is that the distance between the glass and the object is 30cm yk?
So I'm measuring from the glass
Haaaa
Hmmmmmmm
Then what's the answer yk?
Breh
Let's say we get the measurements right?
Now what I do
Knowing its size from this distance?
Well no cuz it's inside the glass yk?
Like a box
Bruh
Fine I'll see what I can do
Hmm
Hmmmmmmmm
Eh it kinda is
Need to read it like twice
And I'll get ot
It*
So ye thanks
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Which operation, between 2 polynomials, multiplication, addition, subtraction or division will not always result in a polynomial? And why?
first of all what does a polynomial mean?
An expression with multiple terms, I think
Idk🐸
the exponents have to be positive integers
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help
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can someone explain the last part
those numbers are 0 at the bottom
no
@frozen matrix Has your question been resolved?
thank you very much
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Is this correct so far?
Yea
okay ty! I tried to solve it. Is this correct?
Yeah looks good
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is this right cuz the radius is not 10
@dusky elk Has your question been resolved?
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What is the max amount of x-intercepts of a polynomial with highest degree of 6?
6
Then how many turning points could it have?
What is the definition of turning point?
Nvm I searched the definition
So any polynomial to power degree n
Means that the max turning points it could have are n-1?
Yeah
Is this always the case?
Yeah
Turning points are real roots of the derivative of the polynomial
Which is of degree n-1
ok thanks
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So I’m need some help with using matrices to solve system of equations there was something like that on my math final and I didn’t know what to do
And maybe some other general algebra 2 stuffs
And then solving the system of equations
<@&286206848099549185>
I found one from homework
<@&286206848099549185>
I generally don’t understand what to do or where to start
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Need help with numbers 3 5 6 and 10
Hi
For #3 what do you think the first step would be
You need to find the area and the formula for area of a circle is πr²
6 2 x 3.14
So 3?
28.26 is the answer?
Yes
Thank you
Do you know how to start #5
Nope
Okay so for #5 I would start by finding the circumference of the whole circle
C=2πr
Then I would divide by 2 to find the length of half the circle
Then I would add 18
I’m confused on this part
Okay so we are given that the diameter is 18
So the radius is 9
So in your calculator
Type in 2 x 3.14 x 9
When you get that answer, that is the circumference of the whole circle
Yeah, now divide by 2
Then add 18
And that would give you the perimeter of half the circle
46.26
Sure
Okay, let me know when you get an answer
226.08?
Okay, how did you start this question
18 x 2 x 3.14
This question asks for the area
And the formula for area is πr^2
We are given that the diameter is 18, and the formula asks for the radius
Don’t forget to divide by 2
So the correct equation you would set up is 3.14 x 9^2
Do you understand?
No, the question above asked for the perimeter which is basically the distance around the circle
This question asks for the area
Use this equation
And then divide by 2
254.34?
That’s the area of the WHOLE circle
Now you need to divide by 2
Are you understanding more now?
127.17
Yeah
10^2 5^2?
What’s the formula for the area of a circle
A = pi r^2
Yes okay
Find the area of each circle
Then divide the area of circle 1 by circle 2
Then you should get your answer
Try solving it, if you have any questions let me know
4
Yea
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does anyone know the answer to this?
@kindred path Has your question been resolved?
@kindred path Has your question been resolved?
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How do i know the original function of this?
Which question are you talking about?
Well if you put x=0 in 5/(2x+10), what do you get?
And you can write the denominator as x - 0
And you'll get your desired form
Yes.
Can you do it now?
I get f(c)) 1/2
Yes, f(0) = 1/2.
Can you tell me what f(x) is?
5/2x+10
5/(2x+10), yes.
And we know that the limit given is just f'(0)
Differentiate 5/(2x+10) and plug in x=0.
-1/10
Yes.
I don't get why i don't derivative x^3
Because there is no limit here
What do you mean?
I mean i should be getting the derivatives of the multiple choices?
Because its missing the limit
Yes.
f(x) = x^3, that is given.
f(2) = 2^3 = 8
f(x) - f(2) = x^3 - 8 = x^3 - 2^3
You should know that a^3 - b^3 = (a - b)(a^2 + ab + b^2)
So x^3 - 2^3 = (x - 2)(x^2 + 2x + 4)
[f(x) - f(2)] / [x - 2] = (x - 2)(x^2 + 2x + 4)/(x - 2) = x^2 + 2x + 4
No derivative involved here.
However, if lim x--> 2 is given with the question
Then you just plug in x=2 in x^2 + 2x + 4
And you will get f'(2), where f(x) = x^3
Wouldn't it be 12
Yes.
Np!
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x^2-x-30=0
Hello
how do I find the roots?
ok
Like square roots
ya
hmm
Oh do you generally want to understand the concept
I understand the concept, BUT
I suck at squaring
meaning factoring
these ones
(a-b)^2
if that's the case
Can I have a question
ya
can we get straight to the point?
sorry
I know the other stuff
but
Basically a number times a number
yea
dying inside
We can write that a squared
dude I know that
-b times -b
how do I factor (a-b)^2
=+b
What factor you can’t factor that
That not a factoring question
You can expand
Not factor it
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It is probably expand
Hey
reopen
.reopen
✅
Okay so do you know how to break up the middle term?
Where is the question
So there's multiple ways of solving quadratic equations
pinned
- breaking up middle term
- quadratic formula
- completing square
which one would you use
May bad I never saw your question
I thought you meant this
definitely not completing the square here I think
but breaking up middle term
would suffice
ig
yes that's unnecessary unless the question commands you to
into -6x+5x
yes so how do you break up the middle term
what do you think is the first step
how do you get those values OTHER THAN trial and error
Find to number that times to 30
that's a very good question to which I do not have the answer
he opened the ticket.
You can use this method
alright
so the general eq is
ax^2+bx+c
so you multiply a and c
yup 🙂
in this case 1 and 30
Yup
(note if it was -1 and 30 you would take -1 and multiply them)
He is a lot better at explaining then me
and multiply them to get a number (this case 30)
and find out its factors
1x30
2x15
3x10
5x6
6 and 5
Lol
no worries
-1x30
-2x15
-3x10
-5x6
1x-30
2x-15
3x-10
5x-6
These are the possible pairs.
are you following?
do you understand till here @vocal tapir
Are they asking you to solve to @vocal tapir
yes
Ok so then I’m this case it is the opposite
what are these pairs of? the product of a and c.
So plus 30 and
he literally went off
Could you help me after
is that PHYSICS???
But do I just write that
I have to write what makes it linear
Ok I got another question then
,rotate ccw 90
Couldn't find an attached image in the last 10 messages.
,rotate ccw 90
I just wana know what to write
you do understand this server is meant for homework HELP, not solve my homeword for me no offense
how did you determine its linear?
This is a practice test dude
ima leave then
I’ll
Kk
@woven crane could you help
Ik it linear
But I dot. How to explain it
.
.
@iron swallow
I am using this channel know
sorry had to do some stuff im back
Please find another one
yes
there's free channels currently
feel free to take advantage
You just closed it
.close
I don't see your username here
there's 2 channels
absolutely more than enough for you
rude
Sorry
I liek explained the question to him above but he think I am wrong
X=30,-1
@woven crane
Help me
??
what is the actual question in this channel?
i scrolled back like 10 pages and couldn't find it
OP seems to want to know how to solve x^2 - x - 30 = 0 by factoring without trial and error
as far as i can tell
@vocal tapir Has your question been resolved?
hmm, well the coefficient of -30 on the constant term tells you that the roots have opposite signs, and the coefficient of -1 on the x term tells you that they must differ in absolute value by 1.. quickly checking the integer factors of 30, only +/-5 and +/-6 are plausible, then you can easily check that (x+5)(x-6) works
yeah I'm sorry at this point
but I'm at work
💀
let me read up
all right I'll give you an evil problem and see how you'll do? since you're so tough
I've read so much and solved like 60 problems for a day different ways
being cocky only complicates your own life
yup here?
yes
I know breaking up the middle term into -6x+5x
but
I forgot how to do it without trial & error
thing is, factoring things directly kind of implies some degree of trial and error and/or just being lucky and spotting it
damn I was always insecure and thought it shouldn't be like that
Are you done
no
If you are @vale wigeon could you please help after
due what the hell, you already have two channels of your own
this guy has been here as soon as I took the channel
oh
he's capping btw
Ya I can’t see them
How do I go to them
stop the cap
click this
see this little arrow to the left of "MATH HELP" - that is clickable, make sure it is pointing down
otherwise channels that you have read get hidden
the "MATH HELP (OCCUPIED)" one, I can see your arrow points right, click it to make it point down
But I can’t
I can't with this guy
Oh
Thank but could one of you come and help after
open it, leave your problem
if in 15 minutes no one has responded
ping helpers
Kk
or use /r/learnmath/ in reddit @iron swallow
one approach is to expand out the square and rearrange into the usual quadratic form
yeah so it breaks up into:
another approach is to square root both sides (but keep in mind there will be a + and - version)
well more generally if you have a^2 = b^2
then a = +b or -b
same deal here
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<@&286206848099549185>
@fossil sundial Has your question been resolved?
From your sketch in (b), you should be able to see that the only way the line y=k could intersect the curve C at 3 distinct points is if the value of k lies somewhere strictly between the two critical values of C. If k is greater or less than both of those values, the line can only intersect once, and if k equals one of the critical values it only intersects C at two distinct points.
So use calculus to find the critical points of C, then plug in those points to find the critical values of C.
@fossil sundial
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Give a definition for the range of a linear transformation T. Suppose that the matrix A represents the transformation T. What is the
range equivalent to in terms of A?
I am confused about the second part
Suppose that the matrix A represents the transformation T. What is the
range equivalent to in terms of A?
Would it be the coloums of A?
We have to write defintions for school
Close. It's the column space of A (the space spanned by the columns of A)
So would this be more right: Simple the range of a linear transformation: T: V- > W is a subspace W. Give a definition for an eigenvalue and eigenvector. What is an
eigenspace
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Hello, I was calculating the derivative of this first function, and I did get the right development. However I don't exactly understand how you should simplify it to get the (x-1)^2*(4x+2)...
You take the common factor out.
$$\begin{array}{rcl}f'(x) &=& 3(x - 1)^2(x + 1)+ (x - 1)^3\&=& (x - 1)^2 \left(3(x + 1) + (x - 1)\right)\end{array}$$
pi over four
If you continue to simplify the second bracket, you should get what they got.
Thank you! It was quite dumb T_T
It's okay, next time you will see it 🙂
please show working
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Help
How?
How do I reduce to the same denominator?
You mean taking the LCM?
How would that help?
i dont think it will 
It's an inequality here. I think AM GM typeofshit
Maybe jensen's idk i don't know what function to assume
try comparing the numerator and the denominator in each fraction
This is something i came up with
A quadrilateral whose diagonals are b+d and a+c and they intersect at right angles. So i got a relationship in angles and sides but idk I'm stuck
@scenic wren Has your question been resolved?
Yep i did that
Took a² out of the denominator and stuff
Didn't understand what to do next
what's a'?
Yes
What next?
I'm confused af
@scenic wren Has your question been resolved?
Got it. First f(a,b,c,d)=f(ta,tb,tc,td) in other words it’s homogeneous therefore we only need to consider it on part of a sphere. Aka, we assume that a^2+b^2+c^2+d^2=1, a,b,c,d>0
Next use Cauchy–Schwarz inequality
That sum $\leq \sqrt{a^{2}+b^{2}+c^{2}+d^{2}} \sqrt{\frac{1}{a^{2}+b^{2}}+\frac{1}{b^{2}+c^{2}}+ \frac{1}{c^{2}+d^{2}}+ \frac{1}{d^{2}+a^{2}}}$
Cogwheels of the mind
$=\sqrt{\frac{1}{(a^{2}+b^{2})(c^{2}+d^{2})}+\frac{1}{(a^{2}+d^{2})(b^{2}+c^{2})}} \leq \sqrt{8} <3$
Cogwheels of the mind
The last inequality comes from 1/x(1-x)<=4
QED. We even found a less upper bound 2sqrt(2)
Take a=b=c=d=1/2 we see that 2sqrt(2) is actually the maximal value
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simple checking my work
\frac{2+x}{1-d}\ge 3 + \frac{(2+x)}{1-d}d^2... d=1/4
$frac{2+x}{1-d}\ge 3 + \frac{(2+x)}{1-d}d^2... d=1/4$
$\frac{2+x}{1-d}\ge 3 + \frac{(2+x)}{1-d}d^2... d=1/4$
! matthewzz
solve the inequality for x?
yes
What have you tried?
$$\begin{align}&(2+x) \frac{1-d^2}{1-d} \ge 3 \
&(2+x) (1+d) \ge 3 \
&(2+x)\frac{5}{4} \ge 3\
&2+x \ge \frac{12}{5}\
&x \ge \frac{2}{5}
\end{align}
$$
秋水
$$\begin{align}&(2+x) \frac{1-d^2}{1-d} \ge 3 \\
&(2+x) (1+d) \ge 3 \\
&(2+x)\frac{5}{4} \ge 3\\
&2+x \ge \frac{12}{5}\\
&x \ge \frac{2}{5}
\end{align}
$$
```Compilation error:```! Package amsmath Error: Erroneous nesting of equation structures;
(amsmath) trying to recover with `aligned'.
See the amsmath package documentation for explanation.
Type H <return> for immediate help.
...
l.62 \end{align}
Try typing <return> to proceed.
If that doesn't work, type X <return> to quit.```
@fickle owl Has your question been resolved?
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What does the arrow mean in this?
imply
Φ(10)=4, as long as n is coprime to 10 we always have n^4=1 mod 10
Oh my bad, yeah imply…
@oak perch you are so into solving all the exercises in this server 
so basically any prime number greater than 5, when raised to the power of 4 has a final digit 1?
Yeah… I am bored…
Yeah, since this tells you n and 10 are coprime
idk what coprime is
Greatest common divisor
okay so what does that mean
? You asked a elementary number theory question without knowing what being relatively prime or gcd means…?
Yeahhh
greatest common divisor of two integers m,n, denote gcd(m,n) is a positive integer d such that
d divides m, d divides n and
Any integer d’ such that d’ divides both m and n, we have d’ divides d
This seems very advanced
It isn’t
Any integer such that …
well you can also do it by calculating (10n+x)^4 for x=1,3,7,9 (why is that enough?). you don't need what cogwheels is doing
this question doesn’t make much sense to you… if you don’t know what Euler function φ means and why a^φ(n)=1 mod n for any a coprime to n
why 10n+x?
so x is the last digit of the number
Yeah, works better for him.
10 times anything always has a 0 at the end
and would it be for x=7,11,13 etc since n is greater than 5
no
x=1,3,7,9. we are going through the possible last digits of all primes greater than 5
okay
in general, if you have any number k with the last digit x, then m can be written as 10n+x for some other number n
so to prove your claim you need to show that every p^4, p>5 prime, is of the form 10m+1 for some m
and a way to do that is to see that every such p can be written as 10n+x for x either 1, 3, 7 or 9 and then calculating (10n+x)^4 and trying to write it as 10m+1 for some m
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ur trying to solve for when the tangent line to f(x) is horizontal
so when f'(x) = 0
That's what I've done here
you've simplified to that poinyt
Derivative, then = 0
oh yea also you've factored it wrong
yea ur good
-x^3
mhm
-4x(x^2 - 3x + 4)
😭 factoring mistakes fkn suck
because you only see them after like 10 mins of staring at ur working
Yeah that's embarrassing I've been solving too many questions tbf
Anyway thanks for the help i don't think I would've realised the mistake for hours
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Do you know what they mean by A, O, and H?
@pale heron Has your question been resolved?
What do you think they are
Yes
👍
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how to prove this
I know no simple proof of that. The only one I ever saw used Bernstein polynomials to quite a significant extent
Stone-Weierstrass
Do you know the Bernstein polynomials ?
Yes
We defined Bnk without the binomial coefficient, so Bn(f) = sum of (Bnk f(k/n)
The end of question 12 is the Stone-Weierstrass theorem
It is not a trivial question, but you can use the fact that Bn(f) -> f to show that f is 0
hm
Using the fact that the integral is 0 for every n
Hint: || by linear combination, the integral of P(x) f(x) is 0 for any polynomial, try to find a useful polynomial||
f is not a polynomial, f is any function
Use the theorem Stone-Weierstrass theorem
With a bit of rigor, it can be made to work
we have to show that
Show what ?
I thought you considered that theorem known ? So then we know that Bn(f) -> f
Where Bn(f) is a polynomial
wait
i was trying with trigonometric functions 😄
if Bn(f) - > f
Bn(f) is polynomial
then integral of P * Bn(f) is 0
or Bn(f) is 0
but Bn(f) - >f
so f=0
😄
im not comfortable with bernstein polynomials
😦
What is P ? You only integral integral of P * f = 0 for any P. There's no f here, so that looks wrong.
P is any polynomial
Then the integral of P Bn(f) != 0
That's not the correct approach
Reread the hint
At least not the one I had in mind
That is a polynomial
Yes
so this is 0
What does that tell you about f ?
it is 0?
is it something with Bnf sum of (Bnk f(k/n)
Let's take for granted (rather than rigorously proving it) for now that this sequence of integrals goes to the integral of f^2. What can you conclude ? There's no hard math in this last step
Should be known property
Elementary property about integrals
Sorry about the delay, was busy in another channel. What can you say of a function that's continuous, positive and whose integral is 0 ?
