An integration problem (1 Viewer)

[vafa]

Find the integration of sinx(1+x^2)^(1/2) dx by using the subsituation u^2=1+cosx

 

[Riviet]

Could you check if your question is correct and make it unambiguous? Thanks.

 

[vafa]

The question is absolutely right.

 

[vafa]

this question has driven me crazy. i have been doing it since yesterday morning. i got that from my friend's book. everything seems ok except (1+x^2)^1/2

u^2=cosx+1
cosx=u^2-1
x=cos^-1(u^2-1)

and then ....

 

[kimii]

this question has driven me crazy. i have been doing it since yesterday morning. i got that from my friend's book. everything seems ok except (1+x^2)^1/2

u^2=cosx+1
cosx=u^2-1
x=cos^-1(u^2-1)

and then ....

but arent u trying to replace your x's with u's instead..
so making x the subject isnt right is it?

i'll do it tonite.. it might be helpful for my trials tomoro lols! i'l reply tomoro with my solution~

 

[webby234]

I'm pretty sure it isn't going to work. Using an integration calculator it says that there is no formula for the integral. Assuming, that is you are attempting to do

(1+x^2)^(1/2) Sin[x] dx

 

[vafa]

ok but then you will have
(1+(cos^-1(u^2-1))^2)^1/2 now its quite complicated and tell me how are you going to deal with that?

 

[Shady01]

dude this si pissin me off as a question, can you confirm you have ritten it rite? and u sure the sub is u(sqrd)= 1+cosx ???????