Search found 173 matches
- Mon Sep 05, 2011 12:15 pm
- Forum: Astronomy & Astrophysics
- Topic: চাঁদ আর মানুষ
- Replies: 17
- Views: 25526
Re: চাঁদ আর মানুষ
আমাদের পৃথিবীতে পতাকা কোন জায়গায় পুঁতা হলে সেইটা প্রথমে নড়ে,এরপর বাতাসের বাঁধার কারনে এর নড়া বন্ধ হইয়া যায়। চাঁদে যখন পতাকা রাখা হইল তখন কম্পঞ্জনিত কারনে এইটা নড়ছে। আর বাতাস না থাকার কারনে এই কম্পন সহজে বন্ধ হয় নাই। তাই ভিডিও করার সময় দেখা গেছে পতাকা নরতেছে।
- Mon Sep 05, 2011 11:59 am
- Forum: Number Theory
- Topic: a congruence problem
- Replies: 10
- Views: 7229
Re: a congruence problem
\[1^7+2^7+3^7+......................+100^7\equiv ?(mod 8)\] Here is my approach... First we divide the sequence in two parts... Even numbers and odd numbers... Any even number is of the form $2n$ ... \[(2n)^7=2^7.n^7=2^3.2^4.n^7=8.2^4.n^7\] Clearly all the 7th power of even numbers are divisible by ...
- Mon Sep 05, 2011 11:03 am
- Forum: Higher Secondary Level
- Topic: Differentiation
- Replies: 17
- Views: 9710
Re: Differentiation
The addition rule fails because of countability. When we say "x times", x needs to be in a countable set. Then you can have a bijection with a sequence from that countable set and you stop when you reach x in the sequence and call that being x times. But the kind of calculus we are doing involves u...
- Mon Sep 05, 2011 10:59 am
- Forum: Higher Secondary Level
- Topic: Differentiation
- Replies: 17
- Views: 9710
Re: Differentiation
You said what we did at first was... \[x\frac{\mathrm{d} (x+x+x+x+..............+x)(x times)}{\mathrm{d} x}\] But it is not what we did at first... At first what we wrote meant that \[x\frac{\mathrm{d} x}{\mathrm{d} x}\] But writing this was wrong... That's why we got $x$ as an answer... Your equati...
- Sun Sep 04, 2011 11:47 am
- Forum: Higher Secondary Level
- Topic: Differentiation
- Replies: 17
- Views: 9710
Re: Differentiation
Avik bhaiya wrote, The first question that tickles my mind: Can you actually define x2 as a sum of x number of x 's??? Please, explain why we can't define $x^2$ like this. s.m. joty, Yeah... I think you got the point... Bravo! Here we are taking $x$ as a variable and constant... That's created the c...
- Mon Aug 29, 2011 1:20 pm
- Forum: Secondary: Solved
- Topic: Dhaka Secondary 2011/9
- Replies: 9
- Views: 14099
Re: Dhaka Secondary 2011/9
The possible values of x are all even numbers except the multiples of 6... $ x= 2,4,8,10,14,16,.....................................$ Now how to find the summation of them... we can do it easily by taking two integers at a time... $ 2+4=6, 8+10=18, 14+16=30, .....................$ We got a new serie...
- Mon Aug 29, 2011 1:13 am
- Forum: Secondary: Solved
- Topic: Dhaka Secondary 2011/9
- Replies: 9
- Views: 14099
Re: Dhaka Secondary 2011/9
For, $x=6, 2^6=64$ which leaves 1 as a remainder when divided by 3.And $6^2=36$ which leaves 0 as a remainder... So how come 6 is a possible value of x?
- Mon Aug 29, 2011 1:00 am
- Forum: H. Secondary: Solved
- Topic: Rangpur Higher Secondary 2011/8
- Replies: 3
- Views: 8749
Re: Rangpur Higher Secondary 2011/8
There are four ways in which the five flags can be hoisted...
1st 2nd pole
4 1
3 2
2 3
1 4
In every possibilities of the 4,the five flags can be hoisted in 5! ways...
So the answer is 4*5!=480 ...
1st 2nd pole
4 1
3 2
2 3
1 4
In every possibilities of the 4,the five flags can be hoisted in 5! ways...
So the answer is 4*5!=480 ...
- Wed Aug 24, 2011 10:15 pm
- Forum: Physics
- Topic: Integration
- Replies: 6
- Views: 4708
- Wed Aug 24, 2011 5:44 am
- Forum: Physics
- Topic: Integration
- Replies: 6
- Views: 4708
Re: Integration
For a brief knowledge there is no alternative for reading a book...
But if you just want the concept I would suggest Khan Academy... It's really great...
But if you just want the concept I would suggest Khan Academy... It's really great...