## Search found 441 matches

Thu Jan 05, 2012 12:00 am
Forum: Higher Secondary Level
Topic: Prove me wrong
Replies: 95
Views: 29516

### Re: Prove me wrong

BTW, Zafar Iqbal's explanation is wrong. In the most common definition of infinity, there is no such things as positive/negative infinity. They are all the same. It's called one-point compactification (the one-point is infinity).
Wed Jan 04, 2012 11:50 pm
Forum: Higher Secondary Level
Topic: Prove me wrong
Replies: 95
Views: 29516

### Re: Prove me wrong

Oh again, the definition!! Who told them about this? I told about the explanation of Sir! Agartala is not Amtala, right? You are saying this just because you yourself can make an explanation with the help of definition. But can you convince a primary student with this explanation of Zafar Sir? Why ...
Wed Jan 04, 2012 3:23 pm
Forum: Higher Secondary Level
Topic: Prove me wrong
Replies: 95
Views: 29516

### Re: Prove me wrong

$1/0$ is undefined because it has not been defined. That has no connection with limit.
Wed Jan 04, 2012 1:08 am
Forum: Higher Secondary Level
Topic: Prove me wrong
Replies: 95
Views: 29516

### Re: Prove me wrong

"it is not possible to reach $\frac10$" because that is not defined. You cannot talk about something that is not defined. So reaching $0$ in that limit would not make any sense. In any case, "limit" does not mean you reach anything. Look at the definition of limit. You never have to reach anything,...
Tue Jan 03, 2012 10:45 pm
Forum: Physics
Topic: The dilemma of Frictionless Surface
Replies: 5
Views: 2617

### Re: The dilemma of Frictionless Surface

raihan khan wrote:they will collide in the center of mass of their system as there is no external force.
Very nice solution
Tue Jan 03, 2012 10:38 pm
Forum: Higher Secondary Level
Topic: Factorial
Replies: 6
Views: 2706

### Re: Factorial

No, that's not a good definition. Because, n things can be per mutated by n! does not mean anything until you have defined what $n!$ is. So you need to define factorial first. Which is done by, $n! = (n-1)! * n$ where $n > 0$ and one initial value. Usually the initial value is taken as $0! = 1$. But...
Sun Jan 01, 2012 2:20 am
Forum: National Math Camp
Topic: বাংলাদেশ অনলাইন ক্যাম্প - ২০১১
Replies: 105
Views: 32259

### Re: বাংলাদেশ অনলাইন ক্যাম্প - ২০১১

I have graded all the problems. Most of you did very well. However, there were some very common mistakes everyone made. 1. Many of you made the mistake of saying things like "Without loss of generality assume $a \geq b \geq c$" even though that was not general. You have to very careful when you say ...
Sat Dec 31, 2011 7:01 am
Forum: Physics
Topic: টর্ক
Replies: 6
Views: 2875

### Re: টর্ক

একটা বল প্রয়গের মাধ্যমে ঘূর্ণন বন্ধ করা সম্ভব হবে, কিন্তু পুরা দন্ডটা (অর্থাৎ তার ভরকেন্দ্র) সেই বলের কারণে বেগপ্রাপ্ত হবে।
Fri Dec 30, 2011 10:21 pm
Forum: Physics
Topic: টর্ক
Replies: 6
Views: 2875

### Re: টর্ক

ও, যদি একটা মাত্র বল প্রয়োগ কর তাইলে দন্ডটার ভরকেন্দ্রের অবস্থান পরিবর্তন হবে। ভরকেন্দ্রের অবস্থান পরিবর্ত না কইরা ঘূর্ণন বন্ধ করতে হইলে দুইটা বল লাগবে।

লব্ধি বল এইখানে টর্কের মাধ্যমে হিসাব করতে হবে।
Fri Dec 30, 2011 3:09 pm
Forum: Physics
Topic: টর্ক
Replies: 6
Views: 2875

### Re: টর্ক

সম্ভব অবশ্যই। বল কয়টা আছে এইটা কোনো গুরুত্বপূর্ণ বিষয় না। সবগুলা বলের লব্ধি হইল গুরুত্বপূর্ণ বিষয়।