#help-17
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so a^3 = 16x^6
4 squared is 16 right
yes
and x^3 squared is x^6
So we can plug it in the difference of squares formula
16x^6 - 25
You can try plugging it in
find what a and b is first
asm
right
We can just do the work inside of the brackets
but then a^3 and a would change because we divided the number by 3?
like
it cant equal the same thing once we divide it by 3, we have to change the power
Uh no
we factored it out
If u distribute that 3 you'll get the original expression
It doesn't affect the powers
asm
isnt that in the parenthesis
okay i get that
So that you can see the a^2 - b^2 better
okay let me paint a scenario because its the only way i see it
sure
If I see ** 48x^6 - 75** , and **16x^6 - 25 ** I'm going to think they need the same type of solving because they generally look the same
but you're saying that it changed
I know but
okay ill just try to roll with that
so now that we have 16x^6 - 25 after we know that we simplified
We simplified it to the point where it can be put into a formula
16 and 25 are perfect squares
oh you didn't point that out
Yea
We simplified it down in order to get the perfect squares
48x^6 - 75
Don't see where to go with that
right
simplifying makes sense
we are definitley supposed to do that
since we got lucky with that factoring find
Yeah, I don't think they would give you an expression where it is unfactorable
so now I have to find the expression that can be multiplied by itself to equal 16x^6 - 25 ?
asm
where $a = 4^2 \cdot x^3$
asm
Yo u agree with that right
4^2 * x^3 = 4x^6 so yes
Same goes for 25
b = 5
now you just use the formula
Don't forget that 3 outside the brackets tho
sure
asm
Mhm
its just 5
Remove 4^2 btw
oh right
a^2 = 4^2
not
a = 4^2
wait no ur right
$a^2 - b^2 = (a + b)(a - b)$
$(4x^3)^2 - 5^2 = ....$
asm
so how come we mention 4^2 if in the equation and formula its never used
What we're essentially trying to do is show that 16x^6 and 25 can be put in the formula
a^2 - b^2
a^2 is indeed equal to 16x^6
man this is tough
We're just trying to find a so that it looks "intuitive" I guess
You don't have to find a and b
thanks for the help tho
bruh wtf is this
5^3 = 125 right
do i gotta make it a = 3x^3
b = 125 not -125 right
No it's never that
its never what
we're dealing with a formula so
b^3
doesnt b^3 = 125
yea
ok ok
alright if i get this right in formula first try im probably good to close it
or somewhat first try
is there a different formula for tihs one
difference of perfect cubes
does it matter which one
I GUESS it is called difference of cubes
Not really sure how you call them in english
Yeah of course
what language is your native?
Georgian
how do i know
Yeah for my problem
both work
is 27 a square of something
no
So it doesn't work
so cube
asm
well yeah that'd be the same i guess
yeah
just ugly numbers if you tried to simplify
like whats the nexts tep
its this one right
Well now u just plug them in the formula
well you showed 2 of them
yea
you can't apply +
so whats the formula called for this one? or if u could post it
the bottom
yea
Yeah, americans ironically call it a state
๐ญ
I mean my country, not my language
it's 5 or 6
asm
They never get added
so 9x^6
yea
this is the only time they get added
you can save these properties later on
alright sweet i got it
Are you doing these from khan academy?
No from my teacher
Oh
10th grade algebra II
If you're really interested into math, I would recommend getting a book
Like an algebra book
potentially
i feel like these type of problems im doing have lots of area for mistake when you're first learning them
in comparison to other units we've learned
Self-study a lot, you might not learn a lot from school (talking from personal experience)
man i gotta shower in 4 hours for school
i feel that
Yeah it's natural
What you wanna do is
Self-study and experiment on your own
Messing around is a good way of learning
And of course, refer to the properties
I heard a way to get good specifically in math is doing problems quickly
so that you don't make up your own math
Well
maybe
Doing problems quickly just trains you at doing problems quickly
You gotta learn how to think about it
yeah im sure
alright im probably gonna close this and headout, thanks for your help. maybe ill be back here another day lol
np ๐
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hi if i wanted to create a transition matrix to model a M/M/3 queue what would it look like?
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i decided to assume that bd = df and ec = ef in the beginning but now after finishing the proof how should i prove that bd = df and ec = ef? also my proof kinda feels wrong
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Help please, how do I solve this?
!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
ah i see where you went wrong
that -1 in the exponent is over the t, not the 125
$8t+125t^{-1}=8t+\frac{125}{t}$
Bonk
probably easiest to multiply by t
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.
$8t+\frac{125}{t}=t\left(8+\frac{125}{t^2}\right)$
Bonk
I did tho-
OHH okay
Why t squared tho if there's already a t outside the bracket
im sure you know $a^ba^c=a^{b+c}$
Bonk
$t \cdot \frac{1}{t^2} = \frac {1}{t}$
so $t^1t^{-2}=t^{1-2}=t^{-1}$
Bonk
yes
OHH
that is whats happening here
David
wait but do we want t^-1 or t^-2
Cos I think it's t^-2 after being differentiated
well, we had t^-1 before, and we took another t out, so we get t^-2
$8t+\frac{125}{t}=t\cdot 8+t\cdot\frac{125}{t^2}=t\left(8+\frac{125}{t^2}\right)$
Bonk
make sense?
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I don't understand how to solve part 4 of this question
the solution I found in part 3 for initial condition $x(0) = x_0$ is $x = (t + x_0^{\frac{2}{3}})^{\frac{3}{2}}$
fallenstars
in the case where $x(0) = 0$, this reduces to $x = t^{\frac{3}{2}}$, right?
fallenstars
I'm confused as to how I'd find more solutions with this initial condition 
I tried multiplying t^3/2 by a constant k, but then x no longer solves the ODE 
I'll take any suggestions
go ahead
dx/dt=3/2x^(1/3), x^(-1/3)dx=3/2 dt, 3/2x^(2/3)=3/2t+C, x^(2/3)=t+2C/3, x=(t+2C/3)^(3/2)
odd
what does the sketch look like?
,w x'=3/2*x^(1/3)
i feel like there can be some intuition places from there

slope field looks like this
I'm not actually sure how to read the initial condition information using this though 
the line that goes through (0,0)
is IC
why is that the case? 
Desmos art
because x(0) = 0
at t=0, x=0
yeah my intuition has been activated
something tells me that the majority of these slopes pass through
I can tell that all the slopes pass through (0, 0)
but not sure how to find them
not all
but the ones above the x axis
also, I still don't follow
I should find em though
but the axes are not t and x 
but im kinda confused how there are infinitely many solutions
mby it has something to do with the exponent?
I don't even understand the initial condition thing yet 
but if the exponent is changed, the function is surely not a solution 
yeah, thats what i figured out
there are at least two solutions
x(t)=0 and x(t)=t^(3/2)
right?
if you find another nontrivial solution you can construct infinitely many
okay nvm
im trying to think of how you can find a third solution
how are you constructing a slope field for the diffeq if the axes aren't x and t
x and x'
my professor told us that the a curve that follows the slope lines is a solution, but he didn't say what the slopes at each pt mean
like when you're representing the slope like that, the visualization implicitly assumes that the horizontal axis is the indep. variable
so I'm confused
math libre says this 
but x seems to be taking the role of t here?
yes but then you have to represent your axes right, you want dx'/dx to be the slopes if you're representing the slope field like that in the image that you sent
idk
what are the slopes here
like if one axis is x' then that's dx/dt
and your slopes should be constant on one axis
is the horizontal axis x'
?
I feel pretty sure that the horizontal axis is x
actually this doesn't make sense anyways, because the space of (x,x') that is allowed in this diffeq looks like x' = 3/2 x^(1/3)
so what is the slope field
like you plotted this, what did you write down to be the slope at each point?
what did you tell it to render the slopes as
if you're plotting x' and x, then you have some curve which represents the allowed states
it'll look like y = 3/2 x^(1/3)
what is the slope grid
I have no idea 
let me pull up desmos 1 sec
okie
how do i make a slope grid
you're asking me? 
here's the one I'm using https://www.desmos.com/calculator/p7vd3cdmei
okay so
so the confusion stemmed from the fact that x was implicitly a function of t earlier, but the calc assumed it was independent
i bet that you can, for each r in R, construct a solution such that x''(0) = r
wait, why do we want to consider the 2nd derivative?
here's a proper slope grid
okay looks like mine now
well, i wonder if it'll help
i mean, let's just try to compute derivatives until we get some degree of freedolm
can you send me what you have actually?
like, how you generated the slope field
g(x,y) = 3/2 y^(1/3)
I don't think I understand 
idk, i'm just throwing out ideas tbh
heck if I know
if you have x = 0 for t < 0 and x = t^3/2 for t geq 0 then that's a solution right
the only thing that you'd have to prove is differentiability at 0
call that solution x = f(t)
then x = f(t-t_0) is also going to be a solution for all positive t_0
i think that's the intention
because the differential equation is invariant under horizontal shift
so the only remaining condition is that x'(0) = 0
but that holds for the new solutions
the solution isn't analytic
wait, it does? 
of course
x(0) = f(0 - t_0) = f(-t_0) = 0 for any t_0 in R?
t_0 has to be positive
okay sure, but even then
then that's good
x will be identically 0 in a neighborhood of 0 then
so x'(0) = 0
and at t=t_0 you switch to the other solution
the condition isn't x'(0) = 0, it's x(0) = 0 
then x(0) is also 0
you need x'(0) to be 0 from the diffeq
so on the left end you get the diffeq holding because x is 0 in a neighborhood of t
and on the right you get the diffeq holding from separation of variables
and then at t_0 you need to prove that the righthand limit as h goes to 0 of (f(t+h) - f(t) )/ h is 0
in order to guarantee that 1. f is differentiable at t = t_0 and 2. the differential equation holds at t = t_0
icic 
I think I got it then 
thank you so much for the help: smay, exiled, Flappie! 
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can someone be my permanent friend and help me with math problems
Not how it works
#โhow-to-get-help
if that's not outside the rules
Bro what ๐
sorry
You can just send your help here and eventually someone will help you
ok sorry
I am new here
Its okay
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Hey, I'm just curious what's wrong with my Excel formula here? I'm trying to analyze a large dataset and I don't see what the issue is with what I have.
=COUNTIFS(B2:B12429, U2, (C2:C12429, E2:E12429, G2:G12429, I2:I12429, K2:K12429), "DesiredOutput")
The logic here is that I want it to count the number of lines where the cell value in the B range matches the cell value in U2 AND where any of the corresponding cells in the other ranges are "DesiredOutput".
So if B2 is "Yes" and "U2" is "Yes" and then any of C2, E2, G2, I2, or K2 are "DesiredOutput" it should add to the count.
@balmy furnace Has your question been resolved?
Excel isn't really popular here. Wolfram and desmos are
Try asking in an excel discord server
There's one called excel
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Hello, can someone check my work for me. I boxed the answers and the way I got them is all written on the respective questions. Thank you I really appreciate it!
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thatโs right
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ten
need some help with how to do this question, new to laplace.
Q: Find i1(t), i2(t), i3(t) for:
$$ \begin{align*} L_1 \frac{di_1}{dt} + R_1 i_2 &= E_1(t) \\ L_2 \frac{di_3}{dt} - R_1 i_2 + R_2 i_3 &= 0 \\ i_1 - i_2 - i_3 &= 0 \end{align*} $$
given the values L1 = 0.005, L2 = 0.01, R1 = 10, R2 = 20, E(t) = 50
I have done this
$$
\begin{align*}
0.005 s I_1(s) + 10 I_2(s) &= \frac{50}{s} \\
0.01 s I_3(s) - 10 I_2(s) + 20 I_3(s) &= 0 \\
I_1(s) - I_2(s) - I_3(s) &= 0
\end{align*}
$$
no clue where to go next
```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.53 ... &= 0 \\ i_1 - i_2 - i_3 &= 0 \end{align*}
$$
Try typing <return> to proceed.
If that doesn't work, type X <return> to quit.```
you have a system of equations
Solve for I1 or I2 and plug into second equation.
repeat until you just get one function
yes and then you have a 3rd equation to solve for one of the functions
ten
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โ
you should have only one variable I1, I2, or I3 by the time you substitute into your 3rd equation
once you get I3, you use the inverse laplace transform to get i3
ten
yea probably partial fractions
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Hi i managed to solve a and b pretty easily but c i cant seem to grt can someone tell me what am doing wrong
Q14 btw
You can use the sine rule on angle ABD and DBC, find their measurements, add them together, then use cosine rule on the segment AC.
I did this but the answer i got was wrong
The book says the answer is 5.15
Huh.
alex <3
I did i just put it straight jnto calc
I...don't think ADC would be 106.7 degrees.
Check your work again.
Yessir
I got 136.332 degrees for DAB though.
Idk I used an online calculator and different triangle that was similar so it may be wrong, was too lazy to do it on my own
But hold on
you're using the sine rule
you can't use sine rule if you don't know any angles in the triangle
Let me try with cosine rule and ill be back
in the question only sides are given
But we do know angles no?
The first part of the question
you only have the sides
Is to figure out angles DAB and BCD
yes
Why cant i use those in sine ruie?
not the same triangle
Angle DAB is in the DAB triangle, with no known angles, only known sides -> Cosine rule
Angle DCB is in the DCB triangle, not in the same DAB triangle, there's again no known angles in the triangle, only sides -> Once again cosine rule
Since angle DAB is the angle at point A.
and angle DCB is the angle at point C.
@hollow kite i got it as 5.15
Thank you very much
So when am dealing with multiple triangles i should use cosine rule?
you can use the cosine rule when you are given two sides and an angle (but in the form of SAS) or when you are given three sides and want to find an angle. However, for the sine rule, you can use it when you have either two angles and a side (in the form of ASA) or two sides and a non-included angle (SSA)
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recall $\frac 1a = a^{-1}$
Steakanator
or perhaps more generally $\frac 1{a^b} = a^{-b}$
Steakanator
so would it be x^-6/2?
not quite
perhaps it would help if you (mentally) rewrote it as $6 \cdot \frac 1{\sqrt x}$
Steakanator
so 6x^-1/2?
๐
that works
fair enough
in that case there's a little more work to be done since you don't have a quadratic yet
how could you get rid of the pesky x^(-1/2)
oh do i times by x^1/2
one of your 'solutions' was x^1/2=-2, do you think this one is valid?
what values can sqrt(x) be?
-
- ?
wdym by that
like +-sqrtx
im speaking solely about sqrt(x)
0 to 1
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Could someone tell me if my proof is sound here? The theroem im trying to prove is : Let n>=2 be an integer. Then the largest integer that is guaranteed to divide n^5 - n is d = 30.
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@fading wasp Has your question been resolved?
it works out well enough
do you see anything that i may be overlooking? @quiet echo
not rly
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on what intervals is the function cube root x increasing?
becase i thought it was always increasing but does x=0 not count as increasing?
Strictly speaking, it's increasing everywhere but x=0
what does it mean for a function to be increasing at a single point? 
any notion of monotonicity (increasing or decreasing) needs to consider pairs of points
yeah but cant a function be increasing within a range
What do you mean by that
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You can prove that 30 divides $n^5-n$ much more simply by factorising:
$n^5-n = n\left(n^4-1\right) = n\left(n^2+1\right)\left(n^2-1\right) = n(n-1)(n+1)\left(n^2+1\right)$
$n(n-1)(n+1)$ must include an even number and a multiple of 3, and so is divisible by 6.
You now only need to establish that when there is NOT a multiple of 5 amongst $n$, $n-1$, and $n+1$, that $n^2+1 \equiv 0$ (mod 5).
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Jay
This is advice for @rron on an earlier question.
Sadly, the bot is grumpy, so...
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$$\text{Calculate the period of a wave with frequency }$$
$$2 * 10^5 Hz$$
Dev
The period is the reciprocal of the frequency
so $\frac{1}{2 * 10^5Hz}$ ?
Dev
oh
$\frac{1}{2 * 10^5}s$
denzio321
ah ok
s being seconds
next?
Yea that's it
you can tidy the expression if you wish
The period is the time it takes for one full osscilation to occur
Right.....
$\frac{1}{2\cdot 10^5}=5\cdot 10^{-6}$
Axe
What's with the elipses ๐ญ
Do you have any doubts?
nope
i thought there was more to it
and forgot which formula to use
And that bascially is it
Thanks!
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Hi can someone do this and explain it
can you not find the minimum and the maximum sum and then count the number of possible sums in between the two?
theyโll differ by a multiple of 3
Problem reduces to finding number of different sums that can be formed using a triplet from the set {1, 2, ..., 675} (Why?)
@pliant violet Has your question been resolved?
Ahhh thats so much simpler. Thanks for the advice. I appreciate it.
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dot product is a projection of one vector on the other
So, in this case, u.w means projection of w on u (or the other way around)
And so, you can see, because they are anti parallel, the dot product is not gonna be positive
(This has nothing to do with whether the vectors are end to start or whatever since you can always move them parallely to arrange them however you want)
@vast shale Has your question been resolved?
yes
You can see it to be antiparallel
I took projection of w on u, so its way easier to see within the given diagram
But, since the dot product is commutative, u.w is same as w.u, so you can do the projection of w on u or u on w, whichever is convenient for you
This is projetion of u on w
u on v is trivial, you can do it easily
Arrows point away from each other in this case, so the dot product would be less than 0
Yep
Well, simpler way is, you dropped a perpendicular from the arrowhead, so you put the arrowhead on the projection
Here, I dropped the perpendicular from the tail end, so I put the tail there
Can you show the other ways to put the arrows?
I am not sure what you mean
If you show the other ways I would tell you why they are wrong or arent
Ok, so you drop the perpendicular (black line) from the 'head' of u
so, the projection must also have the 'head' at the base of the perpendicular
so the arrow goes on the lower part, so this is correct
This one is wrong coz the arrow is only at one end of the perpendicular
Well, you also gotta consider the tail of u
Consider this situation.
Generally, you draw the perpendicular from both ends of u
But in your problem one end of u is already on v, so you dont need the second perpendicular
If you still consider drawing both the perpendiculars, you would notice that the perpendicular from arrow end of u gets the arrow on projection and the non-arrow end doesnt get the arrow on projection
u1 and u2 are same, but you have u1 in your figure, so the second perpendicular is not considered relevant. Its "obvious" how the second perpendicular would be
Uhh, the direction is along the arrow?
I am sorry, i dont get what you mean
Projection of u has its direction, and v has its own direction
If they are same, the dot product is positive, if they are not, the dot product is negative
See, I drop a perpendicular from the arrow end of u
So, the end of the projection there gets the arrow
Like this
And if I draw the other perpendicular, from the non arrow end, because it was from non-arrow end, it wont get the arrow
So I end up with this
Did they not cover that in highschool? I see you got undergrad maths role. Thats why I thought youd know

np
So, same idea here. Non-arrow end gets no arrow
The arrow end gets the arrow, non arrow end gets no arrow
yea
You know basic trig right?
You make a right triangle so that you can make "components" which are trig ratios
u, red projection and blue makea right triangle
so the projection of u on v (red vector) is cos theta times u
thats why the dot product u.v is |u| |v| cos theta
npnp
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In here why to find J or H = A + B - C?
I mean to count J or H, I could just do (4 - 1) + (13 -1) right
Wich remove the double card
Why must 4 + 13 - 1
you removed the jack and hearts card twice
I mean both the 4 and 13 have 1 J and H right, so I just - 1 both
Eh
P(J or H) = P(J) + P(H) - P(J and H)
Yeah right
the 4 jacks already contain one of the 13 hearts
so you just remove one of the double counts
So 4 + 13 - 1
Can you give me one extra example?
if you count the jacks, you get jack spade, jack clubs , jack hearts and jack diamond
if you count the 13 hearts, you get 1 heart 2 heart ... until king hearts
but inside the hearts you count again the jack hearts
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I need help with identifying who this is
Its a Prominent mathematician
Do we known who he is?
Also
I put this without the 1 13/28 mixed number
I just put
41/28
would the answer still of been correct?
My answer
I put the 41/28 and I didn't convert into a mixed number
Would I still of been correct with my answer?
yes
depending on what grade you're in, your teacher may want you to convert to mixed numbers
but as you get higher, improper fractions are usually preferred
And who is this?
No
Btw im not in a Grade, I am in England. In the UK. I am doing a Mathematics Level 2 Functional Skills Maths course and this is the same as GCSE Level, so I was using this website for revision
I will be doing GCSE maths next year
Adult GCSE Maths
How to pass this course?
Can u tell me how?
@oak magnet
What do i do?
What do i do?
ask your teacher whether they want mixed or improper fractions
practice
Are their proper resources for revision? How do I find them?
I did a Past paper and I only got 13 out of 64 Marks, when my teacher marked it. He said the pass mark would be around 36
What do I do?
review the questions you got wrong/had difficulty with
Ramonov said all
@vast shale Has your question been resolved?
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Anyone can help me with part c
What about it
Ap cal
oh part c ?
show working?
shouldnt the integral be more like this?
Oh lord bless you I have been stuck on this question for a while
u understand tho? or is it ok
this the area to find
Ohhh I see
split it like this and u get 2 integrals
bro just integrate x^2 from 0 to 8 and the line from 4 to 8
this would be easier to calculate
How to find Differential Equation
Hmm, I get it now
"easier" to calculate?
both are same things
Yea
nah i mean if ur using pen and paper what i said is quicker i believe
the result is the same obv
cuz x^3/ 3 would be in both integrals
yeah shit i didnt see ๐ญ
Yessir
How to find differential Equation by Separable method
also by "same things" i mean like really same things
School is bit easy on us
apple tesfaye please cant wait no more for da album my goat ๐
u can split integral of x^2 from 0 to 8 into integral of x^2 from 0 to 4 and integral of x^2 from 4 to 8
yeah they are lol
12 more days brother
combine that integral of x^2 from 4 to 8 with the integral of tangent line and boom
exactly
Bro read my Question as well
!help
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they done got my goat to do calc b4 the album ๐ญ
Yessir dropped of school at 17 itโs hard life out here uk what I mean
Atleast Iโm getting my APs done
shit sad af
B4 the album
@lone temple Has your question been resolved?
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.close
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Hello. What is the easiest method for creating Negative or positively definite matrices? It seems like a really long process.
Please don't occupy multiple help channels.
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what's the best way to approximate this integral numerically (where n is a real number except negative integers)
doesn't the result change on changing the value of n?
yes, the result will be in terms of n
yes, the approximation formula has to be infact in terms of n
excactly
because Sยฒ + Cยฒ = 1 it seems like the denom should simplify a lot
if n=1/2
what if it's not, how can i get the best numerical approximation from it in terms of n?
oh a real number I misread
so...?
well for each fixed n you can numerically integrate it
giving you some data point
I suppose you could try to interpolate those results
yes even my calculatore can
but i wanted kinda of a closed form approximation of it
You can substitute tanx = z, that gives you int 0 to infinity ()
Idk if this helps ! But maybe after that binomial expansion or some sort of approximation
oh god
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how do i do this
using IBP
you're not gonna believe it but integrate 3
oh
Integrate 3 and differentiate sin inverse
yeah in inverse trig integrals always try to differentiate the inverse trig function in IBP
i've already said this ๐
mb
integrate 3
differentiate arcsin
this problem teaches you the antiderivative
you donโt need it
so thats a circular question to ask
I hope you know the derivative
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need help with finding the riemann sum for this
!status
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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.
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7. None of the above
seems like you already inputted a value, do you want to check the answers?
@snow bluff Has your question been resolved?
no itโs not right
I need help finding the Riemann sum for both the left-end point and right-end point but I didn't get the right answer
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Why is this not point of inflection if concavity clearly changes
@slow gale Has your question been resolved?
@slow gale Has your question been resolved?
Who says it's not
Show what the website says
It was on my friends laptop
Oh well
Guess it was tweakin
Thanks for confirming guys
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its from the other math server ๐

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ive done a)
dyk how to complete the square
yes
so what part
do u not know how to do
wait it says otherwise
u don't even need to
just differentiate both sides
A' = 1/4 (3 - 2x)
let A' = 0
x = 3/2
idk if u have to prove max but if u do
A'' = -2
therefore max for all values of x
ye
no
or do i have to multiply tat by -1/4
u didn't do that right
oh which bit
so i shouldve multiplied -12.25 by -0.25
yes
