integrate

i found that it will be

but i have guide answer :

Printable View

- February 20th 2013, 03:03 AMmido22problem in integration
integrate

i found that it will be

but i have guide answer : - February 20th 2013, 03:40 AMMathJackRe: problem in integration
split the fraction so ( x/(2x+1) -1/(2x + 1))dx

now let u= 2x + 1

x =(u -1)/2

integrate separately using the above substitution on the first piece

the second is just -1/u integrated - February 20th 2013, 03:44 AMveileenRe: problem in integration
Uhm...

- February 20th 2013, 04:26 AMmido22Re: problem in integration
sorry all but there is power 3 on (2x+1) in the problem

- February 20th 2013, 04:31 AMMathJackRe: problem in integration
That doesnt make much of a difference, use veileens method with the power of 3

- February 20th 2013, 04:48 AMmido22Re: problem in integration
- February 20th 2013, 04:49 AMmido22Re: problem in integration
either my solution correct or the guide answer is correct??

- February 20th 2013, 09:01 AMveileenRe: problem in integrationQuote:

but i can't understand the last two steps in his solution how 2/(2x+1) become (2x+1) ???

Do you know the integration/derivative rules? If not, you should first learn them.

Their answer is the correct one. If that's all you wanted to know, you could have used WolframAlpha. - February 20th 2013, 09:09 AMMINOANMANRe: problem in integration
Mido22

expand the function to get 1/2(2x+1)^2 -1/2(2x+1)^3 and then integrate to get (1-4x)/8(2x+1)^2 +C

it is easy.

MINOAS