oldman's integration method... (1 Viewer)

[freaking_out]

i've been lookin' at oldmans differentials method, and i like it. but i wanna know how u can apply his method for the above question:

#e^(2x)/sqrt(e^x+1)dx

thanks

 

[Exeter]

whats oldmans differentials/integration method?

 

[freaking_out]

Originally posted by Exeter
whats oldmans differentials/integration method?

see this document:

http://www.users.bigpond.net.au/gotmaths/differentials.doc

i mean, how can u not know oldman.

 

[Affinity]

You're fine with whatever method as long as you give the correct answer for integration.. unless they are asking you to prove something, then becareful

 

[Affinity]

well d(e^x + 1) = e^x dx

so your line
= # (e^x+1) - 1 / sqrt( e^x + 1) d(e^x + 1)

= # sqrt(e^x + 1) - 1/sqrt(e^x + 1) d(e^x + 1)

= (2/3)(e^x + 1)^(3/2) - 2 sqrt(e^x + 1) + c

 

[freaking_out]

Originally posted by Affinity
You're fine with whatever method as long as you give the correct answer for integration.. unless they are asking you to prove something, then becareful

yeah, i am aware of that, but i u know its a quick method for other applications of integration, eg. volumes.

 

[Exeter]

Originally posted by freaking_out
see this document:

http://www.users.bigpond.net.au/gotmaths/differentials.doc

i mean, how can u not know oldman.

oooooh yeh i know it, i just didnt know it as OLDMAN"s method, yeh that kicks ass, better than substitution anyday!

 

[underthesun]

Isn't substitution just extra automated working?

 

[freaking_out]

Originally posted by underthesun
Isn't substitution just extra automated working?

ya