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if the bulbs are identical, only 1 way.

if they are distinct 10! ways

Hi,

If

then prove that the difference of the arguments of atleast two of the complex numbers is greater than

. Salute promised!

thanks.

Hi,

If the principal value of the sum of the arguments of roots of the equation

is

, then prove that 'n' must be even and 'k' is positive.

thanks.

regarding de-arrangements, its there in almost every good book. try asit das gupta or any fiitjee package(rankers,classroom,pinnacle). let me know if u just need the formula.

actually, I think the question should have been "If

then prove that

."

This is true, because if you square both sides then you get

,

(the last line follows by dividing the previous line by

, which is real and positive).

yes u right. the info given is not sufficient. many others who I discussed this question with said the same thing. So lets just leave this one. I have only 2 nickles left!

Hi,

If A,B,C represent the complex numbers

respectively on the complex plane and the angles at B and C are each equal to

, then prove that

How do I do this problem? please help.

thanks! u think there is a way to prove it algebraically?

Hi,

If

, then prove that

.

How do I prove this? thanks for your time.

Hey, these types of problems are common. The general method for solving it is this:

if you were to have:

where the p's are prime, then

each of the

's could be "distributed" among the k factors in

(ie,^mj+k-1 C _k-1 ) ways.

x1.x2.x3 = 2^3.3

Hence, ^(3+3-1)C_{3 ^x} ^(3+1-1)C_{1^{. = 30.}}

Notice that this only gives you the number of POSITIVE integral solutions, whereas what is asked is number of integral solutions. If any 2 of x1,x2,x3 are negative, their product still comes out to be 24.

The number of ways any 2 of x1, x2,x3 can be negative is equal to ³C_2.

Thus the total number of solutions = 30 x 4 = 120.

If you are still unclear, check out this post: http://www.goiit.com/posts/list/2402.htm#9606 (scroll to the bottom)

thank you for your words.. I'll do my best to follow your advice. thanks once again.

thanks man.. glad to know I am not alone. I keep getting too frustrated and sometimes slump into a very bad mood and end up wasting a couple of days..

I've done a hell lot of thinking and I realise all these problems can be overcome if we have 100% control of the mind.. an ability to focus and work that extra mile. A person with a very disciplined mind definitely wont have any problems because if we do analyse our mistakes, it seems that it is we who create it outselves..

So, I am really trying to learn to keep the mind in control.. I need all the help I can get..

Any say from the experts?

any more tips anyone???

thanks for your help. i'll do my best..

by the way i just want to ask one more thing. regarding the examination temperament, will it be enough if I just tell myself i did my best.. even today i had an exam which i studied but didnt perform well only because of nervousness...

Hi,

I am aspiring for JEE-2008. I am presently studying in XIth std and have enrolled in FIITJEE classroom program. I know I have the potential and I am working hard but some how or other, something crops up that prevents me from scoring the marks I want. I have done some introspection and divided my weaknesses as such:

1. Lack of concentration/ Complacency: I feel that my attention span is very low. I am unable to sit for long hours at a stretch. I keep getting easily distracted. While studying, I become relaxed after solving a couple of problems and at times divert my attention to other things. Please advice me!! Some people I know suggested meditation to improve your concentration. Is that useful?? I have the 'fire' in me at times.. but it subsides too soon. please help..

2. Examination temperament: I study eveyrhing and I know how to solve to a particular problem. But I am not able to perform at my best during exams. A sort of nervousness crops over me and mind becomes blank. The same problem, I could have solved within a second under normal circumstances.

3. Careless errors: I used to make a lot of careless errors earlier. Through practice, I have put a check to it. But now the problem is... I am wasting tooo much time checking my answers! I doubt every step I do and double check, often wasting a lot of time only to reaslise that I was correct in the first place.

Please help and tell me what I need to do. And in general, how many do I need to put in every day for JEE preparation? And how long should I sit at a stretch while studying?

Thanks for your time.