#help-17
1 messages · Page 290 of 1
you can use the same similar triangles
huh
yup
remember with similar triangles, 16/20 = 12/d = 20/c
since both the triangles have the same angles
i feel like i know what i gotta do its just not there
by other one you mean c right?
yeah
yes
yup
yup
25
yup
ohh i understand it now
yea
i had to make the ratios first
subtract
c = 16+a
or
you can use similar triangles again
since the other side is another similar triangle to the big one
they share the right angle and Z this time
but that would be the most simple way lol
so 9
yup
c = 16 + a
wait how do you get that eqaution tho
oh nvm
im stupid
dont answer that
so would be like
7 - x / 13 - x
x^2 + 5 / x^2 + 20
i gotta multiply
then factor
this one easy
you asking me to verify?
@azure fox if you dont have any more questions, can you say .close
.close
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WHATS MY R FOR 7 IM GONNA CRASH OUT
isn't it e minus when ln(x) = 0? maybe i'm stupid idk
no how is it possible ln =0
maybe i am stupid too
When x is 1?
@brittle zodiac Has your question been resolved?
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can anyone explain me how to know, if i should define 2 variables by t and s or if i should do one variable by t
im gonna be back in like 15 minutes
like basically i dont get the difference between the 2 different systems in this case
back
it depends on the system of equations and whether they are degenerate (for example, in your second example, the two equations are practically the same)
yes
but
the first one is degenerate too right
not really, because I and II are not equivalent
by degenerate do you mean the variables or the 0=0
in some sense, I gives some restrictions, II gives MORE restrictions on top of I
it is a little bit more complicated than that, but let me try to explain
Firstly let us name our equations A_1, A_2,..., A_n (n equations) instead of I,II, for simplicity sake
yeah
So you know, in the second example: A_1+4A_2 gives you the "degenerate equation" 0=0 right?
yes sir
in general if, there is a combination c_1 A_1+c_2A_2+...+c_nA_n (well we have to make sure c_1,...,c_n are not all 0's), that gives you "0=0" we say A_1,...,A_n contains degeneracy
for your first example, we can say I, and II does not contain degeneracy, since aI+bII gives you the equation 0=0 if and only if a=b=0
this might be too much notation at once thrown at you
yesh
i just dont understand how to know what to do
We say A_1,...,A_n is impossible to solve, if c_1A_1,...,c_nA_n gives you the equation 0=C for some constant C.
yeah
for example, a+b=1, and a+b=2 is impossible to solve since A_1-A_2 gives you 0=1
yeah
Here is a very neat fact: if $A_1,...,A_n$ are linear equation (not degenerate or impossible) with m variables, then we must have $n\leq m$ and the number of variables we need to introduce is precisely $m-n$
qwertytrewq
you can think of each non-degenerate equations as "removing one variable of freedom"
yeah
so in your first example, since the two equations are not degenerate, you are removing two "variables of freedom", so you have one variable left to introduce
in the second example, I is the same as II, so you are just removing one "variables of freedom" so you will need to define 2 variables.
yesss
i got that
i understood
studying whether equations are "degenerate" or "impossible" is a part of the study of linear algebra (they use very different notations, but I am defining things like this so that it is more formiliar to you)
so in the first example is ent
sent
u basically try to express every variable through t?
here is an example for you: a+b+c+d=1, a+b+2c+2d=5, 2a+2b+c+d+=-2.
yeah!
because you have freedom over the value of z.
or freedom over the value of x (if you pick x as the value you have freedom over)
man i fucked up
but you can only choose 1, since you can express everything else in terms of x (or z)
i have an exam in 30 minutes
ok I can give you a tip on how to solve these equations
you do it by "reduction"
it is a method of getting rid of unwanted terms
yeah just eliminate u mean
yeah
you can pick A_1, and try to eliminate the "a" term out of both A_2 and A_3
@dense jacinth can you try and do that?
okay
Ill provide another example in the meanwhile
yeah so multiply the first equation by 2?
can you elaborate?
maybe I should be more clear on the procedure
oh we are just removing the "leading term" (which is a) from the rest of the equations
to keep things organized
so we subtract A_2 with cA_1 to get a new equation B_2 where B_2 does not have "a" in it
what would c be?
whats cA_1?
oh
the "2" in "2II"
oh yeah that works
oh
here is a neat fact: Solving A_1,A_2,A_3 is the same as solving A_1,B_2,A_3
so solving a+b+c+d=1, a+b+2c+2d=5, 2a+2b+c+d=-2 is the same as solving a+b+c+d=1,c+d=4,2a+2b+c+d=-2
now can you use A_1 to "reduce" A_3 (remove the occurence of a in A_3 by subtracting some copies of A_1)
uhh
i think we can do this beforeyour exam
there are 2a's in A_3, and one a in A_1, so how do you remove the a's?
how many copies of A_1 do you need to subtract from A_3?
is this confusing?
pls lmk where you got confused on
A_2 is just referring to the equation a+b+2c+2d=5
Im numbering the equations 1,2,3 and denoting them as A_1, A_2, A_3
oh
so A_1 is the equation a+b+c+d=1, A_2 is a+b+2c+2d=5, A_3 is 2a+2b+c+d=-2
our first step is to get rid of the a's from A_2 (using only A_1) so we subtracted one copy of A_1
so we got a new equation B_2 which is c+d=4
is it exam time?
c+d =0
no 😭
its 2a+2b+c+d=-2 I think you might have messed up some computation
2a+2b+c+d- 2(a+b+c+d)=-2-2
oh
-c-d=0
-2-2 is not 0
yeah so you get -c-d=0
so the neat fact tell us that solving for A_1,A_2,A_3 is equivalent to solving A_1, c+d=4, and -c-d=-4
now we get 0=0 right?
no not yet
the next step is to organize our equations
and order it by leading terms
so in this case we don't need to order it
since a+b+c+d=1, c+d=4, -c-d=-4 is already ordered by the leading term
we now can take the second equation, and ask the same questions: How can I remover "c" (the leading term of the second equation) from both A_1, and the third eqution
So if we set B_1 to be a+b+c+d=1, B_2 to be c+d=4, B_3 to be -c-d=-4, we need to reduce B_1, and B_3 using B_2
I'll save you the trouble and tell you that you will get a+b=-3, c+d=4, and 0=0
And from here the solution is very easy to see: set t=b, s=d then a=-3-t, c=4-s
yes
ty
So the steps are:
- Order your equations by the leading terms
- take the first equation, and use that equation to "reduce" the other equations (so that the leading term of the first equation does not appear on the rest)
- Order your equations again.
- Take the second equations, and use that equation to "reduce" the other equations (so the the leading term of the second equation does not appear on the rest)
- rinse and repeat
if it is only 4*3 equations you will only need to do steps 1-4
if you have more equations, then you may need to do more steps
also
but this strategy works for all system of linear equations (after the process, you will ALWAYS end up with a nice system of equations)
this is an overdefined system
can u maybe summarize me
how to go forward on these
Let us try to solve this using the method I summarized above
order the equations first (in this case there is no need in ordering the equations since they all start at x)
Now the second step: can you reduce II and III using I?
you should get ||0=0 and 0=-1||
wait ill be right back
okay so
i mean the solution is on the screenshot😭
i would just do it like how my teacher did it
but 1 thing i dont understand,
yeah but our method is more systematic and always gives you a solution
(it might be more difficult to just "play around and find a way to reduce" compared to a systematic way of reducing our equations)
which part?
wdym by using I sgain
like the solution is 0=0, why dont we take that as solution
like usual
remove the x term from II, III, by subtracting some copies of I
because we get 0=2 for I-III*3
this is saying "if x,y satisfy I, III, then 0=2"
but this cannot be, so there cannot be any simultaneous solutions to I and II
I, II gives you degeneracy, but I,III give you an impossible solution
so I,II,III cannot have solution simultaneously
GL on your exam
so
yeah man ty
oh u r still here i thought u went to take the exam
no like im in the bus 😭
Oh
i understand it ngl
theres a chance the test is more focused on trigonomic functions
which im better at kinda
ok so generally
good stuff
you just do this process over and over again: ditch every 0=0 you see, and whenever you see 0=1 or 0=some non-zero value, you would know that there is no solution
but we could get single values for x y and z right
right
for example the system of equations x=1, y=2, z=3
has single value solutions
its all the same ngl, same process, just a little bit more steps
5*4, 5*5,...., you name it
wait so
i can just memorize
a overdefined function cant have unlimited solutions?
no this is not true
x=1, x=1, x=1, x=1, x=1 is overdefined
but they still have the solution x=1
if a overdefined system of equations do not contain degeneracy, then it will never have solutions. (overdefined means there are strictly more equations than variables)
looks bossy ngl
again you just apply the same rules: reduce II and III using the equation I
and you realize II and III gets reduces to 0=0
so by the "neat fact" I stated a while back, it just suffices to solve equation I
can you like write down what u mean by reduce II and III using the equation I
remove the "x" term from II and III, using I
so II+2/3 I
and III- 1/3 I
you get 0=0 and 0=0
oh
refer to this process
the 2nd step says: take the first equation and remove "x" from II and III
he should have one more line saying something like 2I+3II gives 0=0
anyway what he is saying is I, II, III are essentially the same equations
so we just need to solve for I
its the same as what I did
we "reduce" II and III from I
we get 0=0, throw them out.
you should try doing examples using this process
and see what answer you get.
@dense jacinth Has your question been resolved?
last question
the differnece here is
that the one is infinite
as solution
omg
i understand now
the one is infinite and the other one with the z=t
is also infinite?
or what is ot
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omg is that the old notation for factorials
!noping
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he is my freind lmao its cool
Why?
lmao
yo can i grab a hand
!occupied
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@ripe iron Has your question been resolved?
I somehow managed to show that it equals this sum:
$\sum_{k=1}^n \binom{2k}{k} \cdot 4^{-k} = \sum_{k=1}^n \binom{-\frac{1}{2}}{k} \cdot (-1)^{k}$
MathIsAlwaysRight
idk if thats any helpful tho
what
it would be much easier if it said to find the sum to infinity
it diverges, doesnt it?
I just tried putting it into wolfram alpha
it gives a closed form
it's pretty ugly tho
@ripe iron Has your question been resolved?
@ripe iron Has your question been resolved?
@ripe iron whats the question
its not giberrish lma
tht is just factoril
factorial
its the old notation for factorial
yeah, use latex to create a valid modern question
ugh
fine
$\frac{1}{1!}(\frac{1}{2}) +\frac{1.3}{2!}(\frac{1}{2})^2 +\frac{1.3.5}{3!}(\frac{1}{2})^3 + \dots \text{upto n terms is..}$
rj._.
@neat rose
try harder make it something more readable
i got better things to do
@ripe iron Has your question been resolved?
!nogpt
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
Wdym why not
K so
they often generate output which "sounds correct" but has numerous factual or logical errors.
So
Idc
if you wanna argue this, go to #discussion or something.
somebody else's help channel is not the place.
can also call the mods if you really want to argue.
Yeh cool
actually yeah <@&268886789983436800> we got someone here who knows more about our own rules than us
if people wanted to use AI, they would just use it and not come here.
Ig
Anyway
U can also use daddy khan
He always comes to the rescue
Imma gamble my sons child support
🎀
if you're not gonna help, can you not spam OP's help channel
go to #serious-discussion
i think of wallis formulas
you may try to comprehend
the partial sums can be rewritten as a trigonometric polynomial (with degree 2n)
you'll transform the partial sum
1/2 + 1 ⋅ 3 / (2 ⋅ 4) + 1 ⋅ 3 ⋅ 5 / (2 ⋅ 4 ⋅ 6) + ⋯ + 1 ⋅ 3 ⋯ (2n − 1) / (2 ⋅ 4 ⋯ (2n))
to an integral with the integrand
cos² x + cos⁴ x + cos⁶ x + ⋯ + cos²ⁿ x
You may try to use some math to capture the graphical observation that "the peak gets higher and higher"
hint: ||for any δ > 0, consider the sequence of definite integrals whose integrand is cos² x + cos⁴ x + cos⁶ x + ⋯ + cos²ⁿ x over [δ, π / 2]. (think: why do we want to do so?) the integrand forms a sequence of functions. it's easy to establish uniform convergence to its pointwise limit. in fact, the integral of this pointwise limit over [δ, π / 2] is actually the limit value of this sequence of definite integrals. the rest shld b easy||
@ripe iron Has your question been resolved?
this is jee question lmao they dont even allow a calculator
XD
you don't need a calculator to observe this
the desmos graph is just to provide a graphical intuition
and you can sketch a similar graph without any calculator
you just need to substitute x = 0 into the integrand to observe this phenomenon
as n gets "larger and larger", the peak gets "higher and higher"
'
well the answer is still wrong
Oh I misread the question by overlooking what's on the right of ...
btw i got the answer from elsewhere
im just seeing if someone else cracks it
is that against the server rules or something
then ill take it down
ok
can u send the link to the video
its in hindi
i can understand a bit
sure
18:43➡️ UNSAT (Unacademy National Scholarship & Aptitude Test):- https://unacademy.onelink.me/M2BR/9ikv8hm1
➡️ Iconic Mega Sale Week:- https://unacademy.com/goal/jee-main-and-advanced-preparation/TMUVD/subscribe?plan_type=iconic&referral_code=BEICONIC1REG2L
➡️ Question by Question solutions of IRODOV https://linktr.ee/kotapulsebyunacademy
------...
question number 4
in the
time stamp
thanks
i think u shld be able to do it in the way
the perosn above mentioned
I misread the question
I thought it's to find the limit value of this infinite series, by only looking at the symbols
I don't think there's an easy way to evaluate the integrand for any partial sum above
honestly it was basically that guys idea
it gets cancelled out
when u open the integration with wallis u get this
multipled by pi /2
honestly it was his idea
there was like a tougher version of this
in the adv sample paper they released for 2025
ye
damn gl man
thanks
how was mains(if you dont mind me asking)
ic
2026 aspirant
which college if u dont mind
iit kgp
i meant
possibly
like rn
college?
school
ic
wby
fiitjee
no telengana
fiitjee has many branches
st vincent is my school not coaching lma
yeah i know i have a friend studying in delhi
school plus coaching
they only do both
lmao
yeah its alright
i mean its not the best
or anything
but its ok
once we had an air 3
understandable
once
mine is also somwhere along that
its not thta good compared to delhi
yeah
there is a fitjee near my place
thats still very impressive
yeah but that guy used multiple coaching
ic
fr
no offence but like
air under 10 is just ur born smart hard work only takes u so far
same
yeh fr
than this
.close
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u = 256 - x^2
continue
4096/3
continue
!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.
-(u^1/2)/2
that is the same thing, yes
did you forget the bounds?
Ummm I did make a mistake but I still didnt get the right answer
So ill just continue
can you show your derivation?
Derivation of what sry?
your working out
Ah I just typed it haha so not really its deleted
you should almost always write it donw
yes
.
Ok, I dont understand the bounds thing
Last time I did it and they told me not to do it
the bounds are from x=0 to x=16
1 moment ill find the chat
but now we have u=256-x^2
if we fill in x=0 and x=16
we get the new bounds: from u=256 to u=0
u=256-0^2=256
u=256-16^2=256-256=0
thats probably wrong
I cant find it 😡
But yeah I did it and got the wrong answer, then they told me not to do the bounds and I got the right answer
i cant think of a context where you dont change the bounds
there you also plug in the bounds lol
But I did?
Yes and it was wrong
thats changing the bounds
oh i see now
i suppose you can do the whole calculation without changing the bounds
but you have to be precise with what youre doing
also, trig subs are quite a bit different and tricky sometimes
How do I know when and when not to
you got -u^(3/2)/3
if you dont change the bounds
then you need to fill back in u=256-x^2
to get -(256-x^2)^(3/2)/3 from 0 to 16
if you do change the bounds, then you can keep it at it was before
make sense?
I thought this WAS what it was before?
wdym?
yeah the issue isn't exactly that you did or didn't change the bounds, it's that you weren't consistent with what you were doing
Like we need to convert it from u no matter what
I dont understand
if you take bounds of x=0 to x=pi/2, and plug it into sin^3(x)/3 - sin^5(x)/5, that's fine
if you take bounds of u=0 to u=1, and plug it into u^3/3 - u^5/5, that's fine
So what about the current question?
if oyu wanna be super precise you should do $\int_{x=0}^{x=16} \frac{-\sqrt{u(x)}}{2}\dd u(x)$
if you take bounds of u=0 to u=1, and plug it into sin^3(x)/3 - sin^5(x)/5, that's complete nonsense, it's sort of the same kind of mistake as taking a formula that expects a length in inches and putting in a length in cm
Bonk
well it's the same kind of thing, you have to remember what the bounds you have actually mean and be consistent about it
then you get $\left[\frac{-u(x)^{\frac32}}{3}\right]_{x=0}^{x=16}$
Bonk
Thats what I did no?
no, observe that u is a function of x
we are not plugging in u=0 and u=16
...
we are plugging in u(0) and u(16)
there are two approaches that work
you always take the bounds
for every problem, both approaches work, it's not a matter of "in this case, what do you do"
does this combo make sense?
it's just that you're instead using an approach that never works, by mixing the two approaches in a way that doesn't make sense
-# maybe in special cases
-# yeah occasionally it will get you the right answer by numerical coincidence, or because the bounds wouldn't have been updated anyway, but still
if the bounds you have are x=0 to x=16, then you evaluate those bounds at a function of x
i can show you the general form i foyu like odie
alternatively, you can figure out the bounds in terms of u, which are u=256 to u=0, and then evaluate those in your expression in terms of u
pick one of those two messages and follow through with it the whole way, don't try to do both at the same time
The thing im confused about is I feel like I used the same method for both of them. With the trig example if I took the bounds 1 and 0 (changing the bounds) I got the wrong answer. If I DIDNT change them, taking pi/2 and 0, I got the right answer.
For this question, if I DIDNT change the bounds (0 and 16) I got the wrong answer. if I DO change them (0 and 256) I got the right answer. Im confuseddddd
i think in the trig example you just did it wrong
or you misunderstood smth
we can go through the general form if youd like
sin^2(x)cos^3(x)
sin^2(x)(1-sin^2(x))cos(x)
(sin^2(x)-sin^4(x))cos(x)
u = sin(x)
du = cos(x)dx
u^2 - u^4
Integrates to (u^3)/3 - (u^5)/5
The bounds also change due to the integration u = sin(x)
sin(pi/2) = 1
sin(0) = 0
so the final sum is:
sin^3(1)/3 - sin^5(0)/5
Which step is wrong
It gave the wrong answer so I must have done something wrong
"1 to 0" is bounds in terms of u, which means you put them into u^3/3 - u^5/5, because that's the result in terms of u
first you have u, then you use x
your u bounds are from 1 to 0
your x bounds are from 0 to pi/2
you changed the bounds correctly to the u bounds
but then you filled in the x equation
So it should be sin^3(sin(x))/3 ?
its either $\left.u^3/3-u^5/5\right|_1^0$ or $\left.\sin(x)^3/3-\sin(x)^5/5\right|_0^{\pi/2}$
Bonk
you took the formula with x, and the bounds of u
1 moment im just rereading everything 100 times 😵💫
if you have a question, just ask
Bro its nearly 1am my brain is so cooked, I think I will come back to this one in the morning and see if I can understand it then with a clearer head
you sure?
i think we can bang it out in 10 minutes
for every integral
(general form)
Tbh I think youve explained it in a way I can understand already, my brain just isnt functioning at this hour LOL
If I reread all this tomorrow morning I think ill be able to get it
100%?
alrighty
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Tot morgen hehe
:p
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how solve this with integration by parts
Do you know that it can be done?
Closed by @muted meteor
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In this case, you take the derivative of 3-x, and the integral of e^2x
Much simpler integral after that
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The grades of 300 students are normally distributed with a mean of 50 and a standard deviation of 5. 60 students were higher than Paul. What grade did Paul get?
i learnt this last year but wasnt here so idk
can u look at mine tho
cause i tried urs so
!nogpt
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
@quiet echo can you help me?
Not right now.
60 were higher than paul which means 60/300 or 20% of the population is higher than him which means paul is in the 80th percentile. Get the z score of the 80th percentile and just use the z score formula
Then use this
0,84 = (300-p)/5
Yes
im getting -295,8
we dont know his mean grade
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isnt this question solved directly by using the theorem that i posted?
just apply theorem 3.50 to Σ|a_n|, Σ|b_n| and Σ|c_n| with c_n given as in 3.50
No, since 3.50 assumes both converge, but the question only assumes one does
absolutely*
but if the sum converges absolutely then it converges
The question is basically asking "why does the cauchy product fail if we don't assume absolute convergence?"
Or, well, prove it fails
OH sorry, I have the pictures swapped
np it is mb that i sent them like together
isnt it just this statement ?
My issue is that 3.50 doesn't say the cauchy product converges absolutely
Just that it "converges" which is annoyingly vague
yes but you are given that Σ|a_n| and Σ|b_n| converge, you also know that Σ|a_n| converges absolutely since Σ|a_n|=Σ| |a_n| |
so replace Σa_n by Σ|a_n| and Σb_n by Σ|b_n| in 3.50
then c_n=Σ|a_kb_{n-k}|
so that Σ|c_n|=Σ| Σ|a_kb_{n-k}||=ΣΣ|a_kb_{n-k}|=Σc_n which is convergent
this means that Σc_n converges absolutely no ?
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@sage wind Has your question been resolved?
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okay, quick question
I have started this proof as so
now, I cannot simply say that F is smooth because each component is smooth, right?
starry
hello
idk what ur studying so i cant help u with this
so can u tell me what u are studying
like, I need to find the coordinate rep of this map wrt to the charts on TS^1 and S^1 x R
and then show that that is smooth
is that correct?
idk, tangent spaces rn
write in differential geometry
these are for pre-uni
I am allowed to ask here
• These channels are for pre-university homework-type questions. Broad conceptual questions, as well as questions in university-level topics — are more appropriate in topic-specific channels (Pre-University, Early University, Advanced Mathematics) and in math-discussion.
I'm pretty sure this is the next thing I need to do, but I'm lacking confidence
but sure
I'm not unaware of this
but I choose to ask here anyways
we really need to do away with that section of text
meta suggestion ig
it's not like anyone enforces them 
find charts of both manifolds and show the map is smooth in these coordinates
thats all
yeah so basically what I said then, yeah?
it doesnt even need to be all combinations of charts
one pair of charts, as long as you have enough charts to cover the domain
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ty
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im supposed to evaluate this
bro
i thought it would be 1/2 ln e
can someon ehelp me
so 1/2
!noad
this is correct
its wrong you can check on calculator
the answer key is wrong unfortunately
are you sure you didn't accidentally check the answer for the second question
no these were the first under the 8.3 chapter and the in the answer key they were also the first
also the first two were right
idk why
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Is this right
I thought I put all x with dx
Then what do with 6
its a different solution
wait I'm sorry
i got confused cuz you didn't multiply dx with x^7e^y
So mines right?
you forgot a minus
final step
-e^-y = x+x^8/8 + c
you have to multiply by minus to apply ln on both sides
When I did ln I bring the -y forward and it become positive
Oh so that’s correct answer then?
yep
Wdym take e power both side
Ok so the answer is y= -ln(-6x -x^8/8 + e^-5?
yep
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Hello
we want z right?
so we can raise both sides to the 1/5 power
np!
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can anyone help me with this, its in the 'proof by contradiction' chapter of my textbook and im not very confident in proof and dont know where to start or handle this
Yep, so Even numbers look like 2n, and odd numbers look like 2n+1. Also, being prime means that its only factors are itself and 1. Keep these definitions in mind. To prove this by contradiction, you first assume the opposite is true: There is an even prime that is > 2
Does that much make sense?
yeah that all clear
Alright, so this number is by assumption even, so what does that say about it?
its divisible by 2
Yep, but what did we say the definition of prime was?
Its not divisible by anything but itself and 1 right?
Again, let's prove b) by contradiction. What's the opposite of "there are no two primes whose sum is 1001"?
there are two primes that add to 1001
Yep, and often with these kinds of problems its useful to specify that symbollicaly as well. So one way to do that would be to write that there are two primes p and q such that p+q=1001
What can you tell me about 1001 as a number?
its odd
since they are primes they have to be odd since they have to > 2 so that would mean
2n + 1 + (2n + 1) = 2n + 1
4n + 2 = 2n + 1
2(2n + 1) = 2n + 1 which is a contradcition
You've got the main idea, but one thing's missing
there's an even prime that you need to account for
so assume one of p/q is that prime, and show that it still doesnt work
ok at this point im a little stuck
So you've made the assumption in what you wrote that the primes are >2
but ther's one prime that isn't >2, which is 2
so you have to account for that separately
So assume that one of p or q is in fact 2 (for contradiction)
Say p
then, q+2=1001
with q prime
what's wrong with that?
q would have to be 999 with isnt prime
alright so my conclusion statement would be that 2 primes cannot equal an odd intergar and with the exception of 2 it still cannot be
Oh, one more thing I should note on this sp[ecific step is that for strict correctness, instead of n in the writing of all three numbers, you should use a different letter. As written, it looks like all three are the same number, so the first step should instead read something like 2n+1+(2k+1)=2j+1 but you can reach the same kinda contradiction
alrigth so they all represent a different interger but its showing that the interger its representing is something different for each variable?
Yeah the last few sentences of the proof once you write it out formally will look something like "... which is a contradiction. Thus, 1001 is not the sum of two primes."
Well the definition of a number a being odd is that there's some n such that a=2n+1, bt for a different odd number b, there's still some number that that equation holds for, but it would be different. Thus, its inaccurate to write both a=2n+1 and b=2n+1
no worries, best of luck
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hello, i am currently studying for the Singapore and Asian Schools Math Olympiad, while looong at past paers, i came upun this question which i could not answer
try to look at corresponding spots in the first two columns of a given row
look what the result is in the third column when both the triangles are facing the same direction, and when they arent
or when there is a tringle in one column but not in the other
I belive its either A or D, dont know exactly
Im leaning on D
Tell me if its correct
D is what I got
@autumn flax Has your question been resolved?
Bassically a puzzle that replaces digits with letters
So, how would the above mentioned crypathim work
I have to go now, we will talk later
@autumn flax Has your question been resolved?
The first clue is from g becoming d which means o + d > 9 and g +1 = d
After that you substitute for o + d = 10 + g
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If we have the expression -(x+3)(x-3), does the negative distribute to both terms or only just one?
one
Think of it as (-1)(x+3)(x-3)
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