IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => University => Topic started by: SGVaibhav on December 26, 2009, 03:22:55 pm

Title: INTEGRATION QUESTIONS!
Post by: SGVaibhav on December 26, 2009, 03:22:55 pm

i did not know where to post this topic, so i posted it in both places
____________________________


Guys i have many doubts in integration
i will not be posting them, because they r quite long, so leave those.

now i will put a small doubt that i have.

im posting it in a pic


i do not understand how does the number which comes out is 2??
the number which comes out is supposed to be 4 actually ???

the stuff  // steps i have written is 100 % correct ...

HOW HOW HOW ???

please help fast, because i have a test coming up, and this concept will affect the stuff i learn after this

Title: Re: INTEGRATION QUESTIONS!
Post by: astarmathsandphysics on December 26, 2009, 05:05:08 pm

here

Title: URGENT SMALL QUESTION!! URGENT URGENT !! SMALL QUESTION BUT URGENT!!
Post by: SGVaibhav on December 27, 2009, 04:41:51 pm

confused about integral of  ( x / x^2)

getting 2 answers
posted a picture below...


plz i have a exam tom, and i am waiting for a reply

Title: Re: INTEGRATION QUESTIONS!
Post by: XFlufferzX on December 27, 2009, 05:46:29 pm

Yeahh both of yur answers are correct
according to this rule:

Log x^k is equal to  =  k log x
eg:

Log x^2 is the same as 2 Log x

As is ur question its 1/2 ln x^2

is the same as  ln x

Because when you multiply 2 by 0.5 it gives you 1 -----> ln x

Good luck!!!

Title: Re: INTEGRATION QUESTIONS!
Post by: SGVaibhav on December 27, 2009, 05:49:51 pm

ok 2 more questions

1) so can this thing be simplified ?? ------->        0.5  ln |x^2 + 3|                (half  x   ln absolute value of |x square + 3|)
2), im scannign and im posting

Title: Re: INTEGRATION QUESTIONS!
Post by: SGVaibhav on December 27, 2009, 05:56:49 pm

1 question expresseed clearly

Title: Re: INTEGRATION QUESTIONS!
Post by: SGVaibhav on December 27, 2009, 06:01:55 pm

2nd question

i had a same question
i tried in 2 different ways
i got different answers

and i also checked the answer in the net, and i found a different answer that way also ....

Title: Re: INTEGRATION QUESTIONS!
Post by: SGVaibhav on December 28, 2009, 04:42:21 pm

ok i got the answer :D

Title: Re: INTEGRATION QUESTIONS!
Post by: XFlufferzX on December 28, 2009, 06:09:34 pm

Dats awehsooome! cuz I havent took dat part of integration yet.. :o