Home » Ask & Discuss » Mathematics. » Differential Calculus « Back to Discussion

Differential Calculus

Blazing goIITian

Joined:	13 Aug 2008
Post:	1313

3 Apr 2009 07:51:31 IST

0 People liked this

473

HELP WITH THIS LIMIT !!!

None

Evaluate d limit ......

if its not clear, it is limit n --> infinity 4ⁿ (-1)ⁿ / ( 2ⁿ - 1 )

and i dont knoe wat d answer is !

Share this article on:

Comments (8)

Decoder

Blazing goIITian

Joined: 1 Apr 2007

Posts: 1084

3 Apr 2009 10:35:11 IST

Like 1 people liked this

i m doubtful abt. the validity of the ques. .... (-a)^x ...is not a valid function in general i think...

akshay A NEW BEGINNING...

Blazing goIITian

Joined: 25 Dec 2007

Posts: 1104

3 Apr 2009 10:57:20 IST

Like 0 people liked this

i think ans is 0

divide by 2^n

numerator will be ( 1/2)^n at n = infinity it is 0

and denominator will be 1- (1/2)^n = 1

hence ans is 0

correct me if i am wrong.

akshay A NEW BEGINNING...

Blazing goIITian

Joined: 25 Dec 2007

Posts: 1104

3 Apr 2009 11:07:24 IST

Like 0 people liked this

correcting myself...misread the Q...ans is not 0

KAPIL CVS

Blazing goIITian

Joined: 7 May 2007

Posts: 1724

3 Apr 2009 12:32:45 IST

Like 2 people liked this

THIS QUESTION IS NOT VALID.

now apply l hospital rule once.

now. log( -1 ) is an indeterminate value. which if multiplied by any no. mke that value also indeterminate.

Decoder

Blazing goIITian

Joined: 1 Apr 2007

Posts: 1084

3 Apr 2009 13:20:10 IST

Like 1 people liked this

kapil.... corect ... log(-1) is not indeterminate....log(-1) ..is logically nonsense !!...

Anmol

Blazing goIITian

Joined: 1 Jul 2008

Posts: 439

3 Apr 2009 13:24:54 IST

Like 0 people liked this

ya dats correct..!

pramod

Blazing goIITian

Joined: 24 Jan 2008

Posts: 479

3 Apr 2009 18:56:31 IST

Like 2 people liked this

luk...in a limit if we wanna evaluate the thing without using L'opilt, we try dividing the den and num. and make it sensible...here

with certainity i can say, 2ⁿ-1<4ⁿ limit n-> infinity...., so we see that the deno. <numerator so the answer wud be infinite in magnitude...

its sign wud be (-1)ⁿ but as we donot know the parity of n...this cannot be determined...here if we had the reciprocal of the same limit, it wud have been 0...

cheers...

Mirka

Blazing goIITian

Joined: 13 Aug 2008

Posts: 1313

4 Apr 2009 18:45:22 IST

Like 0 people liked this

thanks guys ! so stu-pid of me !

Quick Reply

Reply

	Some HTML allowed.
	Keep your comments above the belt or risk having them deleted.
	Signup for a avatar to have your pictures show up by your comment
	If Members see a thread that violates the Posting Rules, bring it to the attention of the Moderator Team