#help-33
1 messages · Page 209 of 1
I have all 4
which 4
product, quotient, sum ,, difference
yeah, but you don't have it for x^k where k is an integer
and this is where induction is used
because x^k = x^(k-1) x
okay great
I suppose I could write an induction proof
and then you need to show this for sums of arbitrary length given that you have it for a sum of two terms
but that is also induction
you can just say "a similar induction argument shows this"
if you want to
We start of with the base case , which is $\lim(x_n) \to x$.By the inductive hypothesis, we have $\lim{x_n^m) \to x^m$. then $x_n^{m} \cdot x = x_n^{m+1}$ by the product rule of limits, and we're done
ƒ( wai ina teacup)= I don't know
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
i mean you could clean it up a bit if you were trying to write a really formal inductive proof but like yeah that's the idea
like the wording is a bit weird
are you really not at a point where you would just write "by induction on the degree, x_i^k -> x^k"?
and like they give you full credit?
I could yeah
I only have this course in my 3rd sem, so I'll surely be at that point by then
oh i see, this is self-study
yeah
tbh, i know that some people are gonna get mad at me for saying this, but i really don't think you ought to be so formal with proofs like this. the main thing that you want to be focusing on is "what facts do my assertions use? i should be citing the reasoning either from things i have already proved, or things that someone else has proved, or things that i could easily prove using [X, Y, Z principle, induction, X fact]
because you're just self-studying it
fair,yeah
Tbh, I'm also doing it early so that I can study multi var from shifrin
Atleast need knowledge of open sets, closed sets etc to study shifrin
thanks
.close
Closed by @novel juniper
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
The question is asking for the value of dy/dx
All options are constant numbers
differentiate both expressions w.r.t t and find the ratio
I can't find a way to cancel out
The nominator and demon should be same
Living some constant behind
Show your whole work
.
This is my final answer
Still stuck
I get arcsin(tan2x) and arctan(sin2x)
hmm
@tepid hound Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
@buoyant jetty Has your question been resolved?
Can you translate it into English?
It looks like we have a line and 2 planes
But I don't see an L2
Let L = ..., Π1 = ..., Π2 = ... find lines L1, L2 such that
So we just need any line L1 in Π1?
Mmhmm
Okay so to find L1, we need a point in the plane, and a direction vector in the plane
Any point will do, so let's just set x = 0, y = 0
Then we have 2z = 8
So z = 4
direction can be a multiple of (1,3,2) maybe
So (0, 0, 4) is in the plane
L1 ∩ L have a non empty intersection
We haven't finished yet
The equation of the plane includes a vector normal to the plane
In other words, (1, 3, 2) is normal to the plane
To be in the plane, we need to be tangent to the plane
the normal of the plane. is parallel to all the vectors residing in the plane
Which means perpendicular to the normal
perpendicular*
the direction of L1 has to be perpendicular to the normal of Pi1
yeah, sorry
for direction vector of L1
So we need the dot product with the normal vector to be 0
(a,b,c).(1,3,2)=0
(a,b,c) is direction of L1
we get a subspace of vectors orthogonal to the normal vector of Pi1
a+3b+2c=0
I was thinking of finding the intersection of L and this plane
but idk
Why?
L is just another line
We're finding a different line L1
There are an infinite number of options though
But we just need to make sure the one we choose is valid, so we need a point in the plane and a vector in the plane
The point in the plane can be found by substituting values into the plane equation
And the vector needs to be perpendicular to the normal vector
Those are the conditions we need to satisfy
So we have L1: r = (0, 0, 4) + λ(1, -1, 1)
Does that make sense?
sure
We don't have enough information to specify a single line
direction vector of L1 has to be orthogonal to normal vector of Pi1
we need L1 and L to intersect aswell and we need
L1 to be parallel to L2, I am trying
I was doing them as separate questions mb
yeah is my bad I didnt translated properly
Okay then so we need L1 to be in Π1, L2 to be in Π2, L1 needs to be parallel to L2, and L1 and L2 need to intersect with L
Okay so if L1 is in Π1, the direction vector of the line is perpendicular to the normal vector of the plane
Right?
ye
is a multiple of (1,3,2)
problem is what does L1 parallel L2 mean
they never intersect
yet they have same direction
It's not a multiple
The normal vector of the plane points out of the plane
We need a vector in the plane
So that is perpendicular to the normal vector
okay a vector that is orthogonal to the normal vector
yeah
(x,y,z).(1,3,2)=0
(x,y,z) is the direction of L1
We don't need that any more
If L1 is parallel to L2, then they both have the same direction vector
Right?
I see what you mean now
Right so L1 and L2 both have the same direction vector
Which is perpendicular to the normal of both planes
Aka cross product time
Which is what you did there
what about non empty intersection L1∩L and L2∩L
So now we have the direction vector of L1 and L2
while they being parallel
But we need a starting point for each
yeah
We need L1 to obey the equation for Π1 and also L
And we need L2 to obey the equation for Π2 and also L
Yep that would work
L : X = k(2,0,1) + (0,2,5)
(2k,2,k+5) =(x,y,z)
x+3y+2z=8
2k+6+2k+10=8
4k=-8
k=-2
L1 : X = k(11,-9,8) + (-2(2,0,1)+(0,2,5))
L1 : X = λ(11,-9,8)+(-4,2,3)
Π2 : -3x-y+3z=4
-6k-2+3k+15=4
13-4=3k
9/3=k=3
(2k,2,k+5)=(6,2,8)
L2: X = λ(11,-9,8) + (6,2,8)
yeah
the course I bought made a mistake, is a course taught by undergrads from same university
should be different scalar
Do you have answers for this btw?
using same λ means they are the same and they are not
It's not terrible to do that
yeah, our stuff is correct
But it's not ideal
Okay then all good
If we didn't have answers it would be helpful to check our conditions
So for condition 1, we can sub in L1 into Π1 and L2 into Π2 and check they obey the equations
Condition 2 is easy since it just means the direction vectors are the same
being parallel also mean we need to show they dont intersect
If they have the same direction vector, they won't intersect
they could intersect at one point if they are perpendicular (same direction vector so they are perpendicular directions, no?)
No
,w (1,2,3).(1,2,3)
The direction vector of a line tells us the direction the line goes in
So the two lines are going in exactly the same direction
So they are parallel
Planes have normal vectors that are perpendicular to the plane. Lines have direction vectors that are parallel to the line
If the direction vectors are equal, then the lines are parallel
The only other option is that they are the same line
yeah
So we could check that they aren't
But I don't think that's necessary here
We're just checking our work
The direction vectors being the same is enough
For condition 3, we need to show that L1 and L intersect, so we could just put the equation of L1 into L and make sure it works, and similar for L2
But we have answers to check with here so maybe we don't need that
All good now?
@buoyant jetty Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
@still temple
,w henrycavillbutfat
Wolfram Alpha doesn't understand your query!
Perhaps try rephrasing your question?
Click here to refine your query online
That isn’t like 1 the sum as you pointed out the function has finite discontinuities is the key
@patent fjord Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Can I interpret logistic curve as a graph that grows and decrease exponentially and has a inflection point.
@compact crescent Has your question been resolved?
@compact crescent Has your question been resolved?
It converges at an exponential speed towards both asymptotes
Increasing/decreasing exponentially sounds like the limit is infinite, not finite
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
f(2x - 6) is a horizontal compression by a factor of 2 and a shift right of 3 units right?
and this is the logic i used for that^:
h(x) = f(2x) then h(x - 3) = f(2x - 6)
but then why is this wrong, starting with a shift of 6 units and then compression of factor of 2:
h(x) = f(x - 6) then h(2x) = f(2x - 6)
by order of operations was how i was taught
addition and subtractions
then multiplications and divisions
so translations before stretches
okay but where am i going wrong?
also uh this is right
i'm pretty sure
and so this:
h(x) = f(2x) then h(x - 3) = f(2x - 6)``` is probably right too
i just why a similar argument doesn't work for this:
h(x) = f(x - 6) then h(2x) = f(2x - 6)```
@honest creek Has your question been resolved?
@honest creek Has your question been resolved?
.close
Closed by @honest creek
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hey
I need help
integration
I have this equation
IDK how to express it but
The intrgral notation with unknown letter b over 2 (3e^x+6e^-2x)=0
$\int_2^b 3e^x + 6e^{-2x} dx = 0$
ashy!
evaluate the integral
I know
latex 🙏
e^x remains the same
show your working
yup
okay so
now evaluate it at the bounds
3eb -3e^-2b-3e^2+3e^-4
$3e^b -3e^{-2b}-3e^2+3e^{-4} = 0$
yes
ashy!
then what do you do?
first i would divide through by 3
wait
$e^{3b} -e^{2b}(e^2+e^{-4})-1= 0$
where did u get e
-1 i meant
ashy!
u make x^2=e^1/5?
ashy!
yeah?
wait what
you are solving for b?
the integral is 0
why
so the bounds are the same
@elfin forge Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hey
Hello
so I have this integral AGAIN
and
Snake b over 3 (2x-6) dx=36
how do we find b
can you integrate 2x-6?
$\int_2^b (2x-6)^2 dx = 36$ ?
Denascite
yes
do you know u subs?
do you mean $\frac{(2x-6)^3}{2}$ or $(2x-6)^{3/2}$?
Denascite
first one
good
okay I found the answer but
but
I have another equstion
Question
on another integral
sin^2 x times sin^x
What is its integral
$\int \sin^2(x)\cdot \sin(x) dx$ this?
Denascite
sin^x squared too
i mean AAAA
Sin^2x times cos^2x
this one
Sorry I'm just tired
$\int \sin^2(x)\cdot\cos^2(x) dx$?
Denascite
use a few trig identities
like
sin double angle
@elfin forge Has your question been resolved?
$(a+b)^2 = a^2 + 2ab + b^2$
ashy!
ok wait
if u call that an identity
bruh it's easier than I thought
Okay
and now
my other question
snake ln2 over 0 (1/(1+e^x)
How do you find x?????????
$\int_0^{\ln2} \frac{1}{1 + e^x} dx$
ashy!
yea
u sub
what do you mean
do a substitution
pls Show
wha?
ok scratch that
Closed due to timeout
Use .reopen if this was a mistake.
i thought of a faster way
ok
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
uh
add e^x and subtract it from the numerator
$\int_0^{\ln2} \frac{1 + e^x - e^x}{1 + e^x} dx$
ashy!
$\int_0^{\ln2} 1 - \frac{ e^x}{1 + e^x} dx$
and now u = 1 + e^x
lex.in.a.teacup
$\int_0^{ln2} \frac{e^{-x}}{e^{-x} + 1} dx$
then you reverse chain rule
StrangeQuarkAL
right?
$\int_0^{\ln2} 1 dx - \int_0^{\ln2}\frac{ e^x}{1 + e^x} dx$
lex.in.a.teacup
yes
Ye
@elfin forge Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I will just start off by saying that this is a pretty stupid question
Like they literally invent functions for how the ball moves in time which just don’t follow the rules of physics at all
Regardless let’s do this
Ok so first
It takes 1 second to go from 2 to 10 meters right
And then at the same speed
It goes down to 1 meter
So
Well it should be 1.125
9/8
Ok
Next it goes from 1 m to 5 meters
So it goes 4 meters up
Via a square root curve (which is stupid as gravity isn’t dependent on speed and it should be linear)
So this means that in order to go up a distance of t, it will take ct^2 time, where c is some constant
We know however
That if it goes a distance of 2 meters up, this will take 1 second however
Can you use this to determine c?
A constant is just a number
Basically it isn’t a variable which changes
It’s always the same
yeah, except it is now, every certain amount of meters = (a certain amount of time squared) times something
and im asking for what is that something
okay another way to think about this
if it takes 1 second to go up 2 meters
along a square root curve
how long will it take to go up 4 meters?
4
yes
so in total
it takes 1+1.125+4 seconds
right?
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how can i be sure
this might cost me a mark on my exma tomorrow sir arnavutkoy
i mean you did the steps right? idk what else to say
im sure its correct. im just assuming by option c you mean the 3rd option rather than what is actually labeled as "c"
oh
yeah
why is it b d c e
ok 1 last hting
these are relatively easy
am i correct on these
25 is wrong
think about how you determine where a function has veritcal asymptotes
where the denominator of a function is equal to 0?
alright
so that must mean it has x+3 and x-1
yes
it's c
read d a little more closely
d isn't x+3 and x-1, but x-3 and x+1 instead
which is incorrect
oh cz the vertical asymptotes arent
yeah
sir 1 last problem pls
these questions r easily solved online but i wanna know how to solve them myself
also cause chatgpt is saying d and other classmates solved it as a
$\frac{\frac{a}{b}}{\frac{c}{d}} = \frac{ad}{cb}$
890s
my goal is to help you understand the process to solving it
i want you to know yourself if it's a or d without me telling you
how can you use this information to help you solve the problem? ^^^
im not sure sir
let's look at the expression in the problem
it's a fraction of fractions
using the property i showed above
we can assign each part of the expression to a,b,c,or d
so we flip the fracitons
yep
andcross multiply
not cross, just multiply
sorry
but yea
and before you do foil and all that
i'd say factorize each of them
and try to cancel out common factors
at that point wouldnt there be no reason for foil
cause factoring and canceling
are done
you might have to foil at the end if you have leftover factors
like if you had (x-3)(x+1)/(x-5)
im doing of fuck this shit
sit
sir
would u perhaps tell me the answer
cause ive been sitting at mybtable solving this 80 question worksheet since like 1 pm
and its 10pm
The purpose of this server is to help you learn, not to hand out answers. Do not ask someone to give you the answer directly.
the guy is edging me
ignoring the servers rules is the best way to get help from volunteers. not.
@cold bloom Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I need help with finding the derivatives! And what's chain rule and product rule and when to choose which one to use?
You use the chain rule if you have a composition of functions (that means something like f(g(x)) one function is in the other). Product rule you use if you multiply two functions basically
Got it! I know it may sound a bit stupid but How do I know myself that the equation is going to be multiply two functions ?
f(x) * g(x)
for example
y = ln(x) * x²
f(x) = ln(x) and g(x) = x²
here you multiply ln(x) with x²
Alright thx
One more thing, my doctor wrote = cos (u) at beginning why?
To show the formula
Cos(u) where u is a function
d/dx that badboy gives - u' * sin(u)
@finite scroll Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Could someone please check it
Also for d ,I didn't quite understand what they meant by linear combination for columns
And as for g, I know it's false but not sure how to prove it
Oh I was wondering who math rocks was
It's wai
Could you rephrase that
are they saying b is a column vector ?
let the column vectors be v_1, v_2,\dots, v_n$
\
then $b = \sum_{i=1}^{n} a_i v_i$
for $a_i \in \R$
math_rocks
math_rocks
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
I assumed it to be invertible
So that we can multiply with C inverse on both sides
Can you do tha 
Lol no
1 min
It's false
Closed by @ionic jewel
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Say we have two groups $G$ and $H$ such that $a \in G$ generates $G$ and $b \in H$ generates $H.\$
Does that imply that $(a,b) \in G \times H$ generates $G \times H$?
𝔸dωn𝓲²s
Probably $(a,b)$ can be expressed as $(g^n, h^m)$ where $n,m \in \mathbb{Z}$
𝔸dωn𝓲²s
no
what have you seen for Z2xZ2 ?
𝔸dωn𝓲²s
I have a stupid idea
𝔸dωn𝓲²s
If a+b=2 then n=5x+6y = 120 we get (x,y) = (0,20) hence there must exist a pair (a,b) with order 120?
i shall be borrowing that notation for the modular arithmetic 
I am kinda on the Schlauch right now arghhh
why does n=120 mean that the order of the element is 120?
can you give us a pair with order 120 then ?
😭
I wanted to find an element where it takes at least 120 additions withitself that lead to the neutral element
To show only the existence of a generator
but the order could be any factor of 120, not just 120
yeah no reason the order can't be lower than 120
aight
then you spoiler yourself 
So one group is cyclic the other isn't so they cannot be isomorphic
well yeah if we start with your thing, take an n such that n=0 mod 10 and n=0 mod 12, then you can guarantee n(a,b) = 0 whatever (a,b) are
i.e. all the orders are n or less
and the smallest such n is lcm(10,12)
60
so basically since 1 generates Z_10 and Z_12 we would see if (1,1) would also generate Z_10 x Z_12
but how would you prove this
essentially with the same argument I made above
well you might have another generator who knows, just checking (1, 1) is very light
here you cover all you bases, nothing can ever generate the whole group on its own
@red nimbus Has your question been resolved?
I tried to prove it but I think I am missing something important
𝔸dωn𝓲²s
I just claim that n = lcm
you're just saying stuff you're not proving anything yeah
but like there are 2 cases which lcm covers all. That is ord(g) = k * ord(h) or gcd(ord(g),ord(h)) = 1
ok but it still doesn't prove this
ord(g) = k * ord(h)
why so?
either this or ord(h) = ord(g) * l
I should have said with out loss of generality
(g,h)^n = (g^n, h^n) = (g^ord(g), h^ord(h)) = e
n = ord(g) = ord(h) implies they are equal but suppose they weren't
then n must be a multiple of ord(g) and ord(h)
n = ord(g)ord(h)
Ok I need also the condition that n should be minimal
therefore we take n = lcm(ord(g),ord(h))
that's better yeah
pretty much what I did here
so what I did rn should suffice
yea
Is this fine now?
𝔸dωn𝓲²s
I think the proof is shit
g^n = g^ord(g)
h^n = h^ord(h)
there fore I thought n = ord(g) and n = ord(h)
I think I am being too rash and dont overthink which is badd
(g^n, h^n) = e, means that g^n = e and h^n = e
therefore ... [what can you say about n from these two equalities ?]
n = ord(g) is too restrictive for example
n is a multiple of ord(g) and n is a multiple of ord(h)
yea
tfw n=n^2 always
well n is a common multiple of ord(g) and ord(h) then
yea
eh we all get stuck in weird proof ideas sometimes it's fine
Closed by @red nimbus
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I don't understand the definition of this line function. Isn't the result a set with a single point inside it?
why do you think there would only be a single point in the set?
I see an addition of a point and a vector, which yields a single point.
You get a different point for each t
lots of ways to write the same thing
comma is unusual but its clear from context what its supposed to be
: and | are more common
Closed by @wheat trench
Use .reopen if this was a mistake.
.reopen
✅
Just want to mention that my confusion was because I interpreted that as saying something like "A point + a scaled vector, where the vector's scalar can be any number".
That syntax is ambiguous, and a ":" or "|" would have been better.
.close
Closed by @wheat trench
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
why
Just post the question
<@&268886789983436800>
Channel closed due to the original message being deleted.
If you did not intend to do this, please open a new help channel,
as this action is irreversible, and this channel may abruptly lock.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Anyone know's how to do this question
I need it done in this exact way
try setting y = 2^x
gimme a sec
I have a very simular one already done
almost the same
if you set y = 2^x you can rewrite it in the form a y^2 + by + c = 0 and solve for y
ah, yes, this is what you did here with t = 2^x
i need it done in the same way though
yeah..
ok, so set t = 2^x and rewrite the equation in terms of t
the only thing to figure out is how to rewrite 2^{2x - 1} in terms of t
would you be able to do the steps
what is 2^{2x} in terms of t, if t = 2^x?
what 😭
do you understand the solution to the other problem that you're mimicking?
this
and in my note book i found tihs
which is almost to same
But i dont understand math at all
yes, they are almost exactly the same
especially in english
I just need someone to do the first question like the question that was done in the notebook
my proffesor has a specific way of doing steps
and if i do them any other way
do you understand these steps from the notebook:
- 2^{2x} - 10 * 2^x + 16 = 0
- 2^x = t
- t^2 - 10t + 16 = 0
it would not count
uhm
kinda
2^{2x} - 10 * 2^x + 16 = 0 is a quadratic in disguise because 2^{2x} = (2^x)^2
so if we create a new variable t = 2^x, then we can substitute t and get t^2 - 10 t + 16 = 0
okay
in the new problem, you almost have the same thing, except now instead of 2^{2x} it's 2^{2x - 1}. so first you want to rewrite it into the form a * 2^{2x}. do you see how to do that?
okay
i just tried
to do the question
but im confused withsomething
2^2x -5 * 2^x(what happend to the +1 here)
@modern wigeon
hint: 2^{2x - 1} = 2^{2x} * 2^{-1}
I dont understand
why =
there's no = on the first
how did you get that?
the second line in the first question is wrong
here?
Here is a worked solution to the first question:
- We start with: 2^{2x} - 5 * 2 ^{x + 1} + 16 = 0.
- Since 2^{x + 1} = 2 * 2^x, we can rewrite the left-hand side: 2^{2x} - 5 * 2 * 2^{x} + 16 = 0.
- Simplifying: 2^{2x} - 10 * 2^{x} + 16 = 0
- Now note that 2^{2x} = (2^x)^2.
- So if we set t = 2^x, then we have t^2 - 10 + 16 = 0.
- Factoring, we find that (t - 2)(t - 8) = 0.
- Hence t = 2 or t = 8.
- Substituting back, we have 2^x = 2 or 2^x = 8.
- Hence x = 1 or x = 3.
!nosols
As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.
This is not a solution to his question. It's a correction of the notebook solution he linked.
I retract my !nosols then 
yes
once you understand this solution, you should be able to solve the new problem easily
im
Btw, sorry for the trigger-happy !nosols, I just have to be wary with new members. But I'm seeing your other posts and you seem to be acclimating here very well.
So allow me to reset, and say welcome to the server.
Can't wait to see his name in green
i got
root68
but i cant get root from 48
68*
I don't think that's correct
if you look a bit more closely, you will see that your practice exam problem is extremely similar to the notebook problem
everything looks good until 2^x = t. then you didn't substitute correctly
Its as clear as it can be
What s the goal ?
Maam im trying to help lol
x = 1, x= 3
i did
need it done same as done in here
Lol i didnt see this one
my badd
oh lol
Anw waait
i got
Root68
when im not supposted to
so idk what
uhh
@modern wigeon
helo
i think i got it
as I said before, the mistake is in going from
2^(2x) * 2^(-1) - 5 * 2^x + 8 = 0
to
t^2 - 5 * t + 8 = 0
c needs to be 16not 8
you can't just change c to 16 lol
how did you get from 2^(2x) * 2^(-1) - 5 * 2^x + 8 = 0 to t^2 - 5 * t + 8 = 0
you need to understand the steps to spot the problem
I found 1 and 3
will you have your notebook for the exam?
probbobly
!nosols
As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.
Flip it using ur phone haha
im on pc 😭
Lol nw
@oak fog Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Is my solution correct for x?
seems right
Closed by @lavish granite
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hi, I am kinda hard stuck
𝔸dωn𝓲²s
I literally have no idea how to disprove it
you can probably contradict Phi(0) must be (0, 0)
Derive an expression for $\phi (p/q)$ in terms of $p,q\in \mathbb Z$ and $\phi(1)$
4573r01d|)d357r0y3r 45²
@red nimbus Has your question been resolved?
4573r01d|)d357r0y3r 45²
you can find an element of Q that generates both x and y but there's no element in QXQ that generates both (1,0) and (0,1)
Yeah this is basically a basis argument
but i would then treat them as vector spaces, not groups
Treat them as groups
The argument is that a Q morphism is in fact Q-linear
wtf
Did you read this?
no
I wrote this because its similar to cauchys func equation which you have probably seen
"if f: R -> R is continuous and verifies f(x+y) = f(x) + f(y), then f(x) = f(1)x"
How do we know Phi is linear?
Because it is a homomorphism
huh
no
Yes
The proof lies in the 3 lines of latex there
a homomorphism only shows that the operations are presevered of the structures
it's not necessarily a linear map
Oh i see your issue
Which is why we prove it here
4573r01d|)d357r0y3r 45²
ok i see sory
Yeah so after that you are pretty much done since p/q * phi(1) has a one dim range while QxQ is 2 dimensional
That is what Axe said by "you can find elements of Q that generate both x and y but nothing in QxQ that generates (1,0) and (0,1). "
Indeed say if x=m/n and y=r/s then z=1/ns generates both x and y. But there is definitely nothing in QxQ that generates (1,0) and (0,1)
Can you explain please how the 3rd line implies it's not surjective?
phi(1) is a single vector in QxQ, so its span={ p/q * phi(1)} = range of phi is atmost 1 dim
While QxQ is 2 dim
As spaces over Q
Honestly this is much more straightforward you should read this too
then $(1,0)=\phi(x)=\phi\left(\frac{ms}{ns}\right)=ms\phi(z)$ and $(0,1)=\phi(y)=\phi\left(\frac{nr}{ns}\right)=nr\phi(z)$
Axe
letting $(z_1,z_2)=\phi(z)$ we have $(msz_1,msz_2)=(1,0)$ so $z_2=0$. but then $nr\phi(z)=(nrz_1,0)=(0,1)$
Axe
~~ => 1=0~~
yeah it's a contradiction
Im sure there are a few more ways to do this apart from these two
have you seen (1,0) = phi(p1/q1) and (0,1) = phi(p2/q2), then (p2q1,-p1q2) = p2q1phi(p1/q1) - p1q2phi(p2/q2) = phi(0) = (0,0)
@red nimbus Has your question been resolved?
guess that's what riemann meant, was too stupid to see it
||who said it was a contradiction afterall
||
real 1 = 0 mod 1
Thats the math i like
but then I think we should say p1,p2 in Z\{0} and q1,q2 in N
I guess I am gonna close this, thanks to everybody for the help!
.close
Closed by @red nimbus
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hello
Hi I had a doubt in Jordan Normal Form theorem can you please surprise explain the proof of this theorem with voice clip
@surreal hatch Has your question been resolved?
"surprise"
how does one "surprise explain" something
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
yo guys
i have my mocks starting in a week
give me study advice please 😂😂 how do u guys cram for hard maths in a aeek
Read your book and work on problems. Identify where you struggle and study at those points
not just pastpaper questions?
That's a start too, but you'll have a bias towards the problems you've already encountered.
@neat grove Has your question been resolved?
Closed by @neat grove
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
• Ask your math question in a clear, concise manner.
• Show your work, and if possible, explain where you are stuck.
• After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!
Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Hi, happy new year. Just a little help if I may:
The graph shows a line going into the negatives
but I'm failing to understand how this function can ever be negative
because the absolute value will mean that for any x, the function will yield a positive result.
so |-8-1| + 1 = 10 for example.
What am I misunderstanding please?
Where?
Also, as a correction, absolute values return non-negative values, not necessarily positive (the absolute value of 0 is 0)
2-x is negative for x>2
but the domain for the 2-x "part" is x<1, which doesn't include any part of x>2
I see, just gonna take a sec to process that
Sorry yeah I still don't get it, I get this part:
This makes sense
the red part is the part that's included in the graph
the blue part is where 2-x starts being negative
As I said earlier, none of that blue part is part of our original graph because of the domain restrictions
I see yeah
ooooooh
wait
Ooooh
I get it
yep its not negative, I was seeing it wrong
for g(-1) = 3
correct me if I'm wrong
that makes sense I think yeah
@cunning fiberThanks 🙏
.close
Closed by @woven sinew
Use .reopen if this was a mistake.
