1@mast i marked C & A (acc. to your code),
first is perkins reaction to give unsaturated carboxylic acid → then reduction of double bond then → -COOH to -COCl then → EAS.
this is just my answer.
1708\hspace{-16}(1)\;\; \bf{\int_{-\frac{\pi}{2}}^{\frac{\pi}{2}}\left(x^2+\ln\left(\frac{\pi-x}{\pi+x}\right)\right).\cos xdx}$\\\\\\ (2)\;\; Let $\bf{a_{1}\;a_{2}\;,a_{3},......}$ Be in Harmonic Progression With $\bf{a_{1}=5\;\;,a_{20}=25}$.\\\\ Then Least Positive Int. value of $\bf{n}$ For which $\bf{a_{n}<0}$\\\\\\ (3)\;\; The Eq. of Plane Passing through The point of Intersection of the plane\\\\ $\bf{x+2y+3z=2}$ and $\bf{x-y+z=3}$ at a Distance $\bf{\frac{2}{\sqrt{3}}}$ from $\bf(3,1,-1)$\\\\
1yes , the paper was difficult . i felt physics paper 2 was much difficult than paper 1 also chem was easy though and maths was ok.
71http://www.resonance.ac.in/reso/news/iitjee-answerkey-solutions.aspx
71
Vivek @ Born this Way
·2012-04-08 07:09:47
And yes Paper 2 was more difficult than the Paper 1. (Most of the students at my center found so)
1708
man111 singh
·2012-04-08 07:19:31
For Paper (1)
http://www.prernaclasses.com/IITJEESolutions_2012.htm
1708
man111 singh
·2012-04-08 07:33:08
\hspace{-16}(7)\;\; $Four fair Dice $\bf{D_{1}\;,D_{2}\;,D_{3}\;,D_{4}}$ each having $\bf{6}$ faces no.$\bf{1,2,3,,4,5,6}$\\\\ are Rolled Simultaneously. The Probability that $\bf{D_{4}}$ shows a no. apperaing\\\\ on one of $\bf{D_{1}\;,D_{2}}$ and $\bf{D_{3}}$ is\\\\\\ (8)\;\; If $\bf{P}$ is a $\bf{3\times 3}$ matrix such that $\bf{P^{T}=2P+I}$\\\\ Then There exists a Column Matrix $\bf{X=\begin{bmatrix} \bold{x}\\ \bold{y}\\ \bold{z} \end{bmatrix}\neq\begin{bmatrix} \bold{0}\\ \bold{0}\\ \bold{0} \end{bmatrix}}$. \\\\ Then Which one is Right\\\\ (a) \;\bf{PX=\begin{bmatrix} \bold{0}\\ \bold{0}\\ \bold{0} \end{bmatrix}}\;\;\;\;, (b)\;\;\bf{PX=X}\;\;\;\;,(c)\;\;\bf{PX=2X}\;\;\;\;, (d)\;\;\bf{PX=-X}
1@vivek, man111 how much are you getting in aggregate? what is the cut off?
1708
man111 singh
·2012-04-08 07:36:00
actually I have Completed by B.Tech
I also ask to vivek , aditiya, Rishab, mast and also to you Aritra ,
How Much you guys Getting in IIT-JEE 2012 paper (I) and paper (II)
1
rishabh
·2012-04-08 08:10:29
@man111: the answers i marked in the exam,
1) π22 - 4
2) 25
3) 5x-11y+z = 17
4) (34Δ)2
5) 4
8) PX = -X
1
mast
·2012-04-08 08:13:42
http://imageshack.us/photo/my-images/189/img1168as.jpg/
1708
man111 singh
·2012-04-08 08:32:59
for paper (II)
http://www.prernaclasses.com/IITJEESolutions_2012.htm
1i havn't seen paper2 yet.Any link??
1
rishabh
·2012-04-08 08:45:00
what are you expected marks guys?
i'm in no mood to count.
36some questions like q4 posted by man111 are more of different thinking than direct solving.....
as in this case Δ2/8 = (3Δ/4)2
and one more wonderful question of co-ordinate (the common tangents to the circles)
is also wonderful....!!!
36
rahul
·2012-04-08 11:31:52
sorry.. Δ2/8 = (3/4Δ)2...!!
1
chessenthus
·2012-04-08 11:34:31
Yes I agree that paper 2 was difficult as compared to paper 1.
1
varun.tinkle
·2012-04-08 20:42:34
@ rahul it is direct solving
write the equation in the form 1-cosp/1+cosp =tan^2p/2 =standard equation wirte it in the form s s-1 s-b s-c.... u get it
and coordinate geo one part two was geometry ..... part on eu can actuallly eliminate 2 options on paper and try with the remianing two
1
varun.tinkle
·2012-04-08 20:45:54
7) i have a nice one line sol
let us calculate the number of cases which icondition is not fullfilled
for that d4-6 values
and d3,d2,d1 =5*5*5
thereofore prop =6*5*5*5/6^4 u get it as 125/216
answer =1-125/216
71
Vivek @ Born this Way
·2012-04-08 21:32:47
For 3, I was getting the first coefficient 5 and 7 but not the latter ones.
16) just find the limit of product of the roots of the equation...
you will get it as 1/2...
and only one answer matches....
36
rahul
·2012-04-08 23:38:00
@varun -
ya u r right...
what i did was a bit silly...
2sinA - sin2A2sinA + sin2A = 2 tan2A/2
and in a triangle tan2A/2 = (s - b)(s - c)s (s - a) = s(s - a)(s - b)(s - c){s(s - a)}2 = Δ2/8
rather if i would have multiplied num. and denom. with (s - b)(s - c) then cud get (3/4Δ)2 ...... :P
1i am getting around 132. bad. what is the cutoff anyway? since it was a tough paper any chance of the cutoffs being around 120.
1according to the cut off issued by mst coaching institutes it is 143 ..... even i am getting 141
262cutoff should be around 180 .
