#help-19
1 messages Β· Page 39 of 1
Well think about what you get if you plug in e.g. 1
Uhhh ok
Yeah, we can try x = 1 too
So for x = 0, what can you say?
Is it fine or not
(Why?)
Uhhh it's not like a full answer ig? It's not a single number like 1 for example
Idk
The problem is the square root
Ye
The square root can only have a positive argument
Oh
Don't jump to that conclusion too fast.
What do we need for $\sqrt x$ for it to be defined?
Like what restriction can you put on x
Yeah, so it's defined too
We only worry about things like $\sqrt{-1}$, $\sqrt{-2}$ or $\sqrt{-4}$. \ Can you think of their values? Because there actually is no value in $\mathbb R$.
Uh...
For a solution of sqrt(-1), we would need something squared to be equal to -1
And we can't have that
Ye
Anything squared is greater or equal to 0
Ic
Now here, you don't just have x, but 2x - 7
But the same holds, for $\sqrt{2x - 7}$, we need $2x - 7\geq 0$.
2x >= 7
x >= 3.5
Yeah, almost, I think that was just a wrong calculation on your part, but the idea should be correct
Yeah, so we need x >= 3.5
There is nothing else in the function that could give you something undefined, only the square root is what you have to worry about, because a square root of a negative number is not defined
You can write it in different ways
Interval notation: $[3.5, \infty)$. \ Set-builder notation: ${x \in \mathbb R \mid x \geq 3.5}$ are two examples.
It's all the values that your function can take on. [f(x) = 3 \sqrt{2x - 7} - 8.] What values can a square root take on?
Nope
What values can a square root take on?
Like you can imagine its graph
Positive ones
Ye
Now, $3 \sqrt{2x - 7}$ will go from $0$ to $\infty$ (since $3$ is just a factor on it, and the $2x - 7$ is picked to be $\geq 0$ either way, so it's just like $\sqrt x$) \But we have a $-8$ on it too. That will shift the range
So it will not go from just 0 to infinity, but from ... (hopefully you can fill this in) to infinity
(don't consider the 2x - 7, it's inside of the square root and not relevant here)
We already know that of our function [f(x) = 3 \sqrt{2x - 7} - 8,] the first part, $3 \sqrt{2x - 7}$ is from $0$ to $\infty$. \ It'd not be $7$ to $\infty$, no. \ So we take that $0$ to $\infty$ and shift it down by $8$ because the second part is a $-8$.
So now it's not from 0 to infinity, but from -8 to infinity
Yeah
Ohh
Ok ic
So then for 16.28
It would be like
Uhh
Infinity? As the domain or smth
Idk I'm kinda stupid
[f(x) = \frac{x + 2}{x - 2}.] What $x$ do you think can you plug in? \ (Or asked in reverse: Are there any $x$ that make this impossible to determine (undefined))?
Uhh like you can plug in 0 right?
It is allowed
Oh ok
If you can determine a value for it, then it's allowed
I could determine it's -1
So it's allowed
Oh wait so would the domain be
Like
Infinity
Negative infinity
Two open brackets?
(-infty, infty)?
Almost, but there is one value you forgot to consider
Consider $\frac 1 x$. For what value would that be impossible to determine (undefined)?
Oh is it 2
π
Yes
Ah ic
So everything except 2
Yeah, only the denominator can cause problems
Because you can't divide through 0
Ye
[(-\infty, 2) \cup (2, \infty)] or [{x \in \mathbb R \mid x \neq 2}.]
No
Then maybe you are supposed to use the second
How did you in your class write this? With curly braces {} (set builder notation) or in interval notation (so for example [5, 10])?
Well, the $\cup$ symbol means "union". \ So for example, with $[1, 2] \cup [4, 5]$, you are saying "1 to 2 OR 4 to 5"
Oh
Oh ic
And we are saying here that it's from - infinity to 2), so not including 2, or from (2 to infinity, again not including 2
So in total, we did not include 2
But every other value
Ohh
You could also say $\mathbb R \setminus {2}$.
All of R without 2
That's probably the shortest
Yeah
Saying that is useless and just unnecessary, don't...
Uh ok
So you have $\sqrt{2 + x}$, that's just the same as $\sqrt x$ when looking at the range.
And the range of $\sqrt x$ is $[0, \infty)$, right?
Uhh ok
So now you have a -5
Yeah
That shifts everything down by 5, so your range will be \$[0 - 5, \infty - 5] = [-5, \infty]$.
Yes
Why are they both closed tho?
infinity is not a number, so we never close that one
Yeah okk
I made a typo
No it's ok
So the problem to the rights would be [7,infinity)?
Oh
Thst makes a lot of sense now ye
Btw
Ehst does the @ symbol mean in math
π
Which one do you mean?
I have no clue uhh ok wait let me show you ig
Sure
they say what it means
uhhh
wut
i just dont understand the format then
or what its trying to ask me
ig
It's not a common symbol, they define it as that expression
oh ic
We can define any symbol to mean anything
in a sense
They want to say $\frac{a^3 - b^3}{a - b}$ shorter than having to write all of that out all the time for all variables $a$ and $b$, probably.
$a@b$ is defined to mean $\frac{a^3 - b^3}{a - b}$. So now you can say $1@3$ and it means the same thing as [\frac{1^3 - 3^3}{1 - 3}.]
ok last thing
uhh
i think i already asked too meth bleh
much
i hate spelling
uhh
so if the problem isnt a uhh
square root problem thing
uhh lemme show you
You can ask as much as you want, this is your help channel, lol
oh yeah
its because this is like
stuff i needa catch up on
π
so i haev to figure out most of it out by muself
uhh
so for example
on this problem
how would i find the range
since its not the same format
as the other ones
did i confuse you?
Think about what this takes on for large x
wdym large x
It'll be a huge number divided by a huge number
And the +2 and -2 won't matter
Like imagine we pick $x = 100000$.
Then $f(100000) = \frac{100000 + 2}{100000 - 2}$. That is $\frac{100002}{99998}$. This will be a bit larger than $1$ but very near to it.
yeah
Now take an even larger number. f(1000000000000).
That will be even nearer to 1, only a tiny bit larger than it.
ok
Well, it will never reach 1 if we take larger and larger values.
so would that just be even closer to 1?
It will always be a tiny bit larger than it
so the range would be uhh
Wait, now look at x to -infinity
oh
ok so for example like
-4?
that would be like
1/3
right?
after being simplified
$f(-100000) = \frac{-100000 + 2}{-100000 - 2} = \frac{-99998}{-100002} = \frac{99998}{100002}$, just a bit smaller than $1$. For even smaller (more negative $x$), it'll also just always be a bit smaller than $1$, but never reaching $1$.
So for x to +infinity, it doesn't reach 1, for x to -infinity, it doesn't reach 1
So now let's look at when x gets near to 2, since that's where there is a hole in the domain
From the left (so $x < 2$), if we go very near $2$ (but we're not allowed to reach it, since it's not in the domain), if we pick for example $x = 1.99$, then we'll have [f(1.99) = \frac{1.99 + 2}{1.99 - 2} = \frac{3.99}{-0.01} = -399.] For values even nearer to $2$, left from $2$, the range will go to $-\infty$. \[10pt] Now from the right (so $x > 2)$, if we go very near $2$, if we pick for example $x = 2.01$, then we have [f(2.01) = \frac{2.01 + 2}{2.01 - 2} = \frac{4.01}{0.01} = 401.] Now for values even nearer to $2$, right from $2$, it'll got to $\infty$.
Ok so now imagine the graph, from the left, it approaches 1 from the bottom (since it's less than 1). Then, it suddenly becomes very negative.
Now, starting at the very right, it approaches 1 from the top (since it's greater than 1). Then, it suddenly becomes very big.
The graph will probably help you follow all my arguments
....huh
,w plot (x+2)/(x-2)
Ah ic
Ok
After this argumentation
I'd personally prefer the R \ {1} one
I'd suggest really take your time with these, imagine how it looks like, plotting/sketching these quickly can help
Oh okk
I don't wanna sound like a creep but can I friend you if I need help later
Because this is very confusing
And there's like a lot more things I needs do today
π
I'm not that much on Discord, but if you open a help channel, there'll pretty much always be someone available
Bye
.close
Closed by @ember shell
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
So
How many arrangements of the letters A, B, C, ..., O, P exist such that by removing some letters, one cannot obtain any of the words PONK, DOBA, or COP?
A-P is 16 numbers, therefore 16!
How to continue
@tidal barn Has your question been resolved?
I wonder if its easier to remove all cases that include the words ponk doba and cop
You must remove some sequences
Because for example POABENK
is actually what cant be in it
Cuz u remove ABE
and u have PONK
idk how to do ir
the only interesting part is to prevent overcounting
find the smallest set of removed letters that satisfies the property the question asked for
weβll get to it
U think we can do it quickly in 15mins? Ive been sitting on this for 2h, i need to submit it to teacher
Rn i have there 16! - (16 4) - (16 4) - (16 3) + 3
16 4 thing is combinatirict number
cutting down from 16! is fine but i donβt know what your idea with 16c4 and 16c3s is
Its the number of how to choose 4 positions among 16 total
For PONK
then for DOBA
and finally for COP
so if you remove ABCD for PONK (?) then you have 12 letters left
how does the second 16c4 work
I dont know how to explain tho
I choose 4 positions for word PONK among 16
POABCENFGHK
Example
@tidal barn 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:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
i am so lost solving this question... can anyone help me explain how to find the values of a and b given I found the equation to cn+2?
The correct answers I've gotten was by plugging in a value for n then testing the result in all the inputs so, altough I got most of them correct, idk wth is going on
that looks hard. what grade you in?
uni
university?
<@&286206848099549185>
@harsh prairie Has your question been resolved?
@harsh prairie Has your question been resolved?
@harsh prairie Has your question been resolved?
Closed by @harsh prairie
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
i need some more help
how would i do these
,rotate
take the two points on the lines given. pick one point as your start point and one point as your end point.
- find the "rise": how many grid lines above or below is the second point compared to the first point? this is positive if it's above, negative if it's below.
- find the "run": how many grid lines left or right is the second point compared to the first point? this is positive if it's to the right, negative if it's to the left
- find the slope: the slope is equal to rise/run. make sure you keep the proper sign
@glass shadow Has your question been resolved?
@glass shadow 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:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
can someone help me with the first question
the answer is no
i guess itβs because quadratic doesnβt have an inverse function?
f is a straight line not quadratic
@celest grotto 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:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Question of relative velocity
I find it difficult to understand, can someone please help
The answer is a
Likewise, that's why I asked the question lol
Oh
Just noticed as well
First, convert all units to m/s. Then, the velocity of the bullet relative to the thief is: velocity(police) + muzzle velocity - velocity(thief)
Ok
Why are we adding the velocity of muzzle though?
I thought it was already relative to the ground, seems like it's relative to police
The muzzle velocity is relative to the gun, which is traveling with the police at 45 km/h
that's what it means, how much speed the bullet gains relative to the gun
Ohh, that much was Intuitive I think because when it said muzzle velocity, it didn't mention relative to what
Ohh
I'm getting 72*5/18
20m/s
i found the velocity in km/hr first then I'm converting into m/s..the answer is not matching..
did you convert muzzle velocity to km/h
Ohh no
I didn't see that one was also in m/s mb
Oh now I'm getting 150m/sec
Thanks
.close
Closed by @fossil moth
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
This one is more confusing
If the driver finds other train to be moving in same direction on same track with velocity v, the other train should be move ahead so no collision would happen
And if it's from behind, the driver should be accelerating, not retarding
what about none
Lemme see answer
Looks like the answer is A instead
yess
.close
Closed by @fossil moth
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
hello
.close
Closed by @desert marlin
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Correct Right?
looks fine
Alright
i think this is good aswell
Just double checking
.close
Closed by @cloud bay
Use .reopen if this was a mistake.
!occupied
Someone else is already using this help channel. If you need help with a question, please open your own help channel/thread (see #βhow-to-get-help for instructions).
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
!15mins
Please only use the <@&286206848099549185> ping once if your question has not been answered for 15 minutes. Please do not ping or DM individual users about your question.
!status
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
1
do algebra
wha
use algebra
to solve for y2
you know how you can like
multiply both sides of an equation by the same thing
add or subtract the same things from both sides
right?
yeah
okay
so do that here
try some things
you probably don't want that denominator
try to get rid of it
undo the division
what undos division?
multiplication
right
so that's the first thing you should try
can u jus show me step by step on how u would solve it
.close
Closed by @fast dirge
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
10th sum
@cunning bronze Has your question been resolved?
Question no 10th
@cunning bronze Has your question been resolved?
@cunning bronze 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:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Problem: For any given married couple, P(husband retired) = 0.7
P(wife retired) = 0.4
P(husband retired given wife retired) = 0.8
Choose 2 couples, P(one wife retired and one husband retired) = ?
Where's my mistake:
P(1 wife retired) = 1 - 0.4Β² - 0.6Β² = 0.48
P(1 husband retired | one wife retired)
= 1 - P(2 husbands retired | 1 wife retired) - P(0 husbands retired | 1 wife retired)
= 1 - 0.8 β’ 0.7 - (1 - 0.8) β’ (1 - 0.7)
= 1 - 0.8 β’ 0.7 - 0.2 β’ 0.3 = 0.38
Answer = 0.38 β’ 0.48 = 0.1824
(correct answer = 0.2016)
Probably in the P(one husband retired given one wife retired part)
I'm not sure how you calculated that
Adding a footnote
The logic doesn't seem right
Edited
Edited again, but it should be 0.2 β’ 0.3
no, I don't think it should be
you need P(husband retired | wife didn't retire)
Which is definitely not 0.7
Sorry I'm not used to conditional prob notations
P(0 husbands retired | 1 wife retired) is (1 - 0.8) β’ (1 - 0.7)
Former for husband with retired wife, latter for husband with unretired wife
ok, P(2 husbands retired | 1 wife retired)
The .8 is for the husband who's wife retired, right
What about the .7
But .7 isn't the probability of a husband retiring, given his wife didn't retire
P(husband retired | wife not retired) is not just 0.7
Right
Let me work this out
Yea thanks a lot
I forgot that having a condition changes everything
I'd go with the Venn Diagram method
.close
Closed by @civic storm
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
but when u have ln8 and ln2 ^3, they're not the same
thewizardofOU
As written down
oh i see
I misremembered how ln works
I thought the 1/a goes on the outside
thxs for clearing that up
.close
Closed by @mortal stump
Use .reopen if this was a mistake.
yw
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
ye
Closed by @wraith horizon
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how to solve for a?
ik my hand writting is bad but you guys get the point
Whats the rest of the question
thats it
owhw
wait
now
CP = PH = OH = CO
and CP = 5
Closed by @rugged parrot
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
$\int \sqrt{1-x^3} \dd x$
Adam Chebil
How do I evaluate this??
difference of cubes?
Then?
I alreasy tried that, but I didn't know what to do after difference of cubes
${ \int \sqrt{ \left( 1-x \right) \left( 1+x+x^2 \right)} \dd x$
(1-x)(1+x+x^2)
(1-x) + x(1-x) + x^2(1-x)
U sub doesnβt work here
i realised
This integral doesnβt have elementary solution
You can use binomial to get the first few terms but thatβs it
,w integral of sqrt(1-x^3)
Adam Chebil
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
How did u know that?
Because Iβve seen it before
So there's no function such that its derivative is sqrt(1-xΒ³) ??
Not elementary ones
What does elementary mean here ?
In mathematics, an elementary function is a function of a single variable (typically real or complex) that is defined as taking sums, products, roots and compositions of finitely many polynomial, rational, trigonometric, hyperbolic, and exponential functions, including possibly their inverse functions (e.g., arcsin, log, or x1/n).All elementary ...
Closed by @fervent hound
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
For 8a?
Can some tell me is this is right?
jsut to confirm, what is on thy 3rd row from the bottom, you wrote (1/2)e raised to the power of -20(1/2), or to the power of -2(1/2)?
either way, -20(1/2) nor -2(1/2) arent equal to 1
My bad my hand writing pretty bade itβs supposed to be -2x
Itβs supposed to be -2xe^-2x + e^-2x
=0
Oh
do you want to know what exactly you missed or should i let you figure it out yourself?
Excatly what I missed I have been stuck for a while
-2(1/2) is not equal to 1, but -1
other than that, everything is perfect (i think)
Ok thank you
dw i once told my teacher that 2+2 = 2
Closed by @wintry viper
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
what are x_i and how do they relate to your matrix A
you still need to define the x_i
yes them being orthogonal is important
you need to use that fact in your proof
also you should do part a before doing part b
none of your calculation proves anything
struggling with what exactly?
part a) tells you to show $||x_1 + x_2||^2 = ||x_1||^2 + ||x_2||^2$
riemann
assuming $x_1, x_2$ are orthogonal.
riemann
use that and expand the left side
you've expanded them both correctly so far
but you haven't proven equality yet
apply the first or second one
yes
that's not how proofs work
you start with one side ONLY and do algebra on it until you get the other side
you can basically delete everything to the right of the equal signs
no
delete doesn't mean replace with original
like if you type
abc = def
and delete def
what do you get
yes delete and remove are synonyms
still haven't removed those
after your last line here, then you use orthogonality to get the result
look up the definition of orthogonal
should be in your book/notes
QuasiStar θΆ ζ°ζ
this only makes sense in 2 dimension
you have an n dimensional vector
the definition of orthogonal in n dimensions is their dot product is zero
so this is correct
@hazy gazelle Has your question been resolved?
You keep putting things you need to delete
Everything to the right of the equal sign on the first two lines should be deleted
Closed by @hazy gazelle
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
!show
Show your work, and if possible, explain where you are stuck.
$\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=\frac{bc+ac+ab}{abc}$
artemetra
i'm just asking, did you understand what i did here
not yet bro
haha be patient
i'm not giving away solutions like that
$$\frac{bc+ac+ab}{abc}=1$$
$$\implies bc+ac+ab=abc$$
artemetra
if the sum of three number are equal to 1 and the multiply of the three numbers also equal 1 what thats mean?
-> (b-1)(c-1)(b+c) = 0
u still didnt solve or ur done?
its not too hard just think a lil bit
i think we dont solve here?
π
bro what is that π π
god i know i will hate maths even more in the coming years
Closed by @balmy thistle
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
help
i need help
with
the square root of 4
ur trolling?
when a*a = b, then sqrt(b) = a, for a >= 0
if ur actually not trolling
mb dude

huh
" Square root of a number is a value, which on multiplication by itself, gives the original number"
@gentle abyss 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:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
I've been working on this proof. After trying a few values, it's like 1.6... so I'm thinking it is the golden ratio. Anyways, the sequence isn't monotonic, it alternates like up and down.
So I tried some subsequences
like the even subsequence I have proven is increasing, and the odd is decreasing
if I have that they are both bounded in the proper direction respectively both by phi, then I'm done
but I don't know how to get started on showing this bound. Any help?
do you have any facts that will help you prove (a_n) converges?
not find the limit but just that it converges
If it was monotone and bounded
which it is not
if it was cauchy
which is hard
if both the even and odd subsequences converge to the same value (which is what I'm trying)
since the even and odd subsequences are monotonic I just have to show they're bounded
i'll just add that if it does converge, say to $X$, then we have $$\lim_{n\to\infty} a_n = 1 + \frac{1}{\lim_{n\to\infty} a_{n-1}}$$ or equivalently $$X = 1 + \frac{1}{X}$$
layla
which does narrow it down to the golden ratio
right
(it's either the golden ratio or that other solution but that one is negative)
right
so maybe it'd be easier to show it is cauchy
but I got stuck trying that aswell
i'm not sure yet but just wanted to point out it will be enough to show (a_n) converges
very fibby
i will note that 1.5 <= a_n <= 2 for n>1
Bounded yes but not monotonic
(so you can prove that the sequence is contractive)
I'm not sure what contractive means
|a_(n+1) - a_n| <= r|a_n - a_(n-1)| for some constant r<1
hm I don't think that's the expected way, never seen it before
does that work?
you can also try this
the sequence is always rational
and the numerator/denominator are the fibonacci numbers
So are you both indicating that it would not be possible to show these are odd/even subsequences are bounded ?
that's what I wanted to try
but if I can't do that I can try other stuff I guess
well they're certainly bounded
Right but bounded by phi
like
I've shown the even sequence is monotone decreasing
if I can show it has GLB=phi
i think you can just prove that they converge to the same limit
right
without bounding by phi
I was trying to use monotone sequence theorem
yes
well we know the sequence is bounded
and the odd/even terms are monotone
so that guarantees their convergence
then you know what they converge to
well I know
but I haven't shown it
without knowing their sup and inf
right?
the recurrence relation will tell you exactly what they converge to
I can do that algebra
not on the whple sequence
but on the subsequences
too
okay
dang
ye

I noticed some mistakes in my algebra for one of the directions but other than that I'm good now
.close
Closed by @desert marlin
Use .reopen if this was a mistake.
great
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
How's the sum of roots equal to zero here?
vieta
multiply out (x-x1)(x-x2).. and compare the coefficient of x^3 with the given polynomial
Closed by @rain tundra
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Ola
I need help rq
These different parameters
ax+bx+cx+d
d is on y-achse
c on x-achse
a is amplitude
what does b do
Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.
all good
@lethal cipher Has your question been resolved?
i was talking about sinus function
and yh ur right b period
pi pi half
i found a very good video so im good
Closed due to timeout
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
how did it get 7 as the maximum value
it has a restricted domain
from the graph
the bolded section is the section that's actually part of the domain
where is the highest point on that section located
None of what you said sounds right
(I sent that like 8 minutes ago)
more than half of it was german
_<
Lol, and it was more than hour old
I'm on my phone using data, there was a connection issue
Yea happens, hope ur wifi gets better
my wifi broke once and after that i got a new one delivered
2 days like without good wifi
πͺΏπ
@mystic saffron Has your question been resolved?
Closed by @next dove
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
Am I getting this right?
Find the probability of each outcome when a biased die is rolled, if rolling a 2 or rolling a 4 is three times as likely as rolling each of the other four numbers on the die and it is equally likely to roll a 2 or a 4.
P(1) = x
P(2 or 4) = 3 (P(1) + P(3) + P (5) +P(6))
P(2 or 4) = 3(x + x + x + x)
P(2 or 4) = 12x
P(2) = 6x
P(4) = 6x
P(1) + P(2) + ... + P(6) = 1
6x + 6x + 4x = 1
16x = 1
x = 1/16
P(2) = P(4) = 6/16 or 3/8
P(1) = P(3) = P(5) = P(6) = 1/16
I think the question meant three times the probability of rolling a 1 (which is equal to that of a 3, 5, or 6)
@winter rapids 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:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
why is the solution to $\frac{x}{2x-1}-1\geq 0$ not just $x\leq 1$
Jash
multiplying by a negative number reverses the direction of inequality
e.g. 1<2 but -1>-2
so how do u solve it
you have to split the problem into the cases where the value you want to multiply is strictly positive or negative
Closed by @junior ether
Use .reopen if this was a mistake.
Send your question here to claim the channel.
Remember:
β’ Ask your math question in a clear, concise manner.
β’ Show your work, and if possible, explain where you are stuck.
β’ After 15 minutes, feel free to ping <@&286206848099549185>.
β’ Type the command .close to free the channel when you're done.
β’ Be polite and have a nice day!
Read #βhow-to-get-help for further information on how to ask a good question, and about conduct in the question channels.
!status
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
do you know how to find the maximum of a function
you've done calc right
No
Is this like a university math serverβ¦.
Yes
so you can write any quadratic in this form. a scales (stretches/squishes) it vertically, b translates it horizontally, and c translates it vertically
an untranslated parabola (b=0, c=0) has its vertex at 0,0
Ok but on a test i cant just use my phone to do all that (its tmrw so)
when the parabola is translated the vertex is translated with it so the vertex will be at (b,c)
so you'd complete the square
Can also use -b/2a
idk how well im explaining this
Faster
yeah
Ok i did that n got -4.9 (t + 5)^2 -125.14
Wrong right
yeah
So then what is it
Try using -b/2a it's easier
Gives you the x value of vertex then sub in for y value
just solve the quadratic equation for it for A
it will give two x values
replace those two x values with T and test them out
you may even get a negative
take the highest x value you got from the 2
and then replace it with T, thats the max heigh
now to find how long the arrow would be in the air
you got the answer for A with what i said above, so replace h with the answer you got
for example, lets say it was 20 or something, now the question would become
20 = -4.9t^2 +50t + 2.3
i assume you know how to solve from here
switch 20 to the other side and it becomes
-4.9t^2+50t-17.7
do the quadratic equation again
OHHH
its literally just the same thing lol
they just changed the equation a little
do the same steps
What abt the 40% gravityβ¦
that was already accounted when they changed the equation
OH
it becomes this with 40% less
Okay
all they did was change the x^2 variable
ill tell in a few minutes
Alr
a
ok so i had to go somewhere but i figured it out while walking
so they lose 400 people per 0.10 increase
that means 4000 people per 1 increase
how many times does 4000 go in 12000
4000*3 = 12000
because obviously 4*3 = 12
that means they need to increase it to the price of 3 dollars to lose all their cusotmers
from some testing, it seems that at 2 dollars, they make the max revuene.
the formula is R = P*(12000-400 multipled by (p-1/0.10))
R = revunene
p = price
at either 8400 customers, which is 1.9 dollars, they make 15960 dollars. at 7600 customers and 2.1 price, they make 15,960. and it only goes downhill from there
but at 2 dollars, at 8000 customers, they get 16000, whcih is the highest
@glossy drift
oh alr
Type .close
@glossy drift Has your question been resolved?
Closed due to timeout
Use .reopen if this was a mistake.