@blue There is no alpha hydrogen.

Or in other words, you cannot have a double bond without some sort of rearrangement.

You would need a pentavalent carbon to form a double bond.

@blue Can you derive the functional relationship : f(x)*f(1/x)=f(x)+f(1/x) just by starting with (1+x^n) ?

How ?

Oh !!! Yeah. I fithot

*forgot.

How was your exam?

Do you know marks vs rank for wbjee?

Around 125

Ok. Hmm.. Lets see what happens this year

I could not do more than 5 chems.

But not desired stream

Hmm

CSE or ECE or IT

What does EE involve?

I am thinking to drop this year

And study Chem.

JEE around 2000 - 3000 rank will yield nothing

Any droppers here?

@Yashas How much have u benifited from a year?

Really??

Have you done the restitution problem of physics in wbjee?

No.. A steel ball

Bouncing for 10 secs

Remember?

The options were such shit.... I could reach to answer (25√2-1)/(25√2+1) ... But none of the options matched... Then realised later that it's value is 17/18

How did you perform in maths?

I attempted 70 and got 2 wrong

And Chem?

Hmm

How do you study chem?

I mean how do you remember things in chem?

Do you understand everything in Chem?

And understood inorganic?

See this ;

Hmm... See later... I am unable to figure out how to do it !!!

@Yashas Are you there?

@MadhuchhandaMandal You can study chem in 1 month

@MadhuchhandaMandal It may seem that I dropped just because I did not get into any IIT with CS or EE or a good branch but that isn't the only reason.

It is up to you to decide.

I did some good CS work this year.

So now I have more things like "Did X, Y, Z in high school"

some really good programming stuff

+ took SAT and other high school tests

@blue I dono yet -,-

@blue o0

I was able to finish one chem chapter every day!

except block chem

cud study properly

I had 24x7 to study though.

school might cause problems

@MadhuchhandaMandal Write JEE Advanced then decided whether to drop or not.

You can do chem in 30 days!

thoroughly

I am going to start a full revision of all chem chapters in the next 20 days

I am bad in chem too

You don't need extensive practice like math or physics to be good at chem.

@Yashas But my problem is that I have never read chemistry till date

@MadhuchhandaMandal does not matter

It seems very silly... But I could never understand a topic in Chem

Atomic Structure = modern physics

Physical chem is tooo easy to learn

Nuclear Chemistry = Modern Physics

Chemical Kinetics = just read it once and get the idea

Inorganic & Organic

you'll never forget

Inorganic = study chemical bonding and you'll get around 10 marks in Advanced

if you don't get time, don't do a detailed study in block chem and qualitative analysis

do coordination chemistry

metallurgy

do the block chem and qualitative analysis at the end

you can study the entire organic syllabus in one week

with 6 hours per day

you'll need some practice after studying if you are studying for the first time

@blue I am not :|

@Yashas Thanks. I will try.

Hydrocarbons = 2 hours

Aromatic Compounds = 3 hours

Carbonyl Compounds = 3 hours

Carboxylic acids, esters, etc. = 1 hour

Alcohols = 2 hours

Alkyl Halids = 6 - 8 hours

what did I miss?

Amines and other nitro compounds = 2 hours

+ 15 hours practice

1000 problems

yea biomolecules and polymers will fetch you 6-10 marks

@MadhuchhandaMandal When you read, refer to the syllabus!

I know all kinds of bs in biomolecules

and they aren't even in the JEE syllabus

only 5 polymers are there for JEE Advanced I think

@MadhuchhandaMandal If you haven't done physical chem, do it first.

It is easy and scoring.

In inorganic chem do Chemical Bonding , Coordination compounds, metallugy

You will get 20 marks from ^

Will studying ncert be of any help?

No

It won't help for Chem bonding, coordination compounds and metallurgy

it helps but you need more

perfect coordination compounds

you'll need around 4-5 hours

don't pay attention to nomenclature

learn crystal field theory properly

Ok. Thanks very much

People around me are saying not to study anything new !!!

@blue Thanks !!!

@MadhuchhandaMandal This depends.

Now I am confused!!!

If you don't know anything in chem, then you study important chapters.

Not studying and revising what you know will get you less marks than if you study important chapters which you don't know.

I see

Don't keep studying until the last day though

then do a revision of all math and physics till 15th

Study chem till May 10th

then do a chem revision

@blue If he doesn't even score 15 or something in chem then he won't even get a rank.

there are cutoffs for subjects in JEE Advanced

@Yashas Really ??????

Yes, they are very small though.

10% or something

I haven't studied chem... :(

Ok

See this question

@MadhuchhandaMandal Study physical chem (too easy to learn) then study chemical bonding, coordination compounds and metallurgy (very important) then do organic.

if time permits, do the rest of inorganic

you already know atomic structure

periodic properties is too easy

needn't study

@MadhuchhandaMandal Y = F/A * l/(delta l)

increasing gradually = l keeps increasing

suddenly = smaller l

it will break faster

But the answer??

let me try

Hmm.. Take ur time

@blue C)

I was out for a checkup :-)

How did you proceed?

?

@blue I disappeared :P

I would have guessed C

because it shouldn't depend on mg at all

if the normal length (T = 0 ) was l0

then you can make a new normal length l0' which includes mg

the answer shouldn't depend on the initial tension at all

Ok I get it!!! @blue you consider that the Fo is removed and F is applied (THE weight still hanging) ?

Hm...

physics.stackexchange.com/q/72696/81224 I want the answer to this question and there seems that I cannot do substantial edits to bump it to the homepage. Please help.

@ApoorvPotnis You need not consider acceleration to be 0

You can expand binomially to neglect the constant acceleration

But it will again yeild x^(3/2) in result

can we not use Bayes theorm

you could, but I just don't remember it well

you could easily tweak my solution a little bit to introduce the Bayes theorem in between

\mathbb{P}(\text{the signal transmitted was green }\cap\text{ B received a green signal}) = \mathbb{P}(\text{the signal transmitted was green }\cap\text{ A received a green signal}\cap\text{ B received a green signal})+\mathbb{P}(\text{the signal transmitted was green }\cap\text{ A received a red signal}\cap\text{ B received a green signal})

And how you have written this

@user123733 Are you sure that answer is 23/40

?

My approach is : P(Og)= Probability that original signal is Green. P(G)=Probability that received signal is green. (Red gets represented by P(Or) and P(R) respectively )

P(Og|G)=(P(Og) P(G|Og))/(P(Og) P(G|Og) + P(Or) P(G|Or))

P(Og)=4/5 P(Or)=1/5 P(G|Og)=(3/4*3/4+1/4*1/4) P(G|Or)= (3/4*1/4+1/4*3/4)

P(Og|G) [after putting above values]= 20/23

@MadhuchhandaMandal I get a different answer. The possible sequences ending in G are RRG, RGG, GGG, GRG. (RRG means emitted red, received by A as red, received by B as green.)

The probabilities are RRG=(4/5)(3/4)(1/4)=(12/80), RGG=(4/5)(1/4)(3/4)=(12/80), GGG=(1/5)(3/4)(3/4)=(9/80), GRG=(1/5)(1/4)(1/4)=(1/80).

Sorry just realised I have got probabilities for R and G mixed up.

The probabilities are RRG=(1/5)(3/4)(1/4)=(3/80), RGG=(1/5)(1/4)(3/4)=(3/80), GGG=(4/5)(3/4)(3/4)=(36/80), GRG=(4/5)(1/4)(1/4)=(4/80). Probability that G was emitted if G received at B is (36+4)/(36+4+3+3)=(40/46)=(20/23). Same. Sorry.