Mind Spirit Share

This forum is for those who willing to share whatever come across the mind.
 
HomeSearchUsergroupsRegisterLog in

Share | 
 

 [Maths] Proving~~

View previous topic View next topic Go down 
AuthorMessage
withoutwax
Professor
Professor
avatar

Posts : 101
Join date : 2008-08-02

PostSubject: [Maths] Proving~~   Sat Sep 13, 2008 4:34 pm

Exam's over..but we never let our brain stops..

Just found a few interesting question..try it out~~

Prove

{integral} 1/sinx dx=ln{tan[1/2 x]} + C

and

{integral} 1/cosx dx=ln{[cos x]/[1-sin x]} + C

Happy working it~~Whahaha bounce bounce bounce bounce bounce
Back to top Go down
View user profile
withoutwax
Professor
Professor
avatar

Posts : 101
Join date : 2008-08-02

PostSubject: Re: [Maths] Proving~~   Tue Sep 16, 2008 8:08 pm

No one is willing to giv a damn-try on this??
Back to top Go down
View user profile
mia

avatar

Posts : 63
Join date : 2008-08-01

PostSubject: Re: [Maths] Proving~~   Wed Sep 17, 2008 12:24 am

Hmm...

{integral} 1/sinx dx
I got is ln tanx...
cos differentiate sinx is cos x and integrate 1/sinx would be ln sinx...
haha.... so eventually is (ln sinx)/(cos x) and thus ln tanx
XD.... I know it must be wrong.... but thats how I see it...

for {integral} 1/cosx dx
I thought will get (-ln cos x)/(sin x) ?
LOL...
cos differentiate cosx is -sin x.... how dya get 1-sinx?? confused
Back to top Go down
View user profile
Death
V.I.P.
V.I.P.
avatar

Posts : 368
Join date : 2008-08-05
Location : Milky Way Galaxy

PostSubject: Re: [Maths] Proving~~   Wed Sep 17, 2008 12:31 pm

mia wrote:
Hmm...

{integral} 1/sinx dx
I got is ln tanx...
cos differentiate sinx is cos x and integrate 1/sinx would be ln sinx...
haha.... so eventually is (ln sinx)/(cos x) and thus ln tanx
XD.... I know it must be wrong.... but thats how I see it...

for {integral} 1/cosx dx
I thought will get (-ln cos x)/(sin x) ?
LOL...
cos differentiate cosx is -sin x.... how dya get 1-sinx?? confused

I think we has to use trigonometric identity,sin^2 x + cos^2 x = 1,or the sin x = 2t / 1+t^2 or something..
Back to top Go down
View user profile http://chosen-paths.blogspot.com
withoutwax
Professor
Professor
avatar

Posts : 101
Join date : 2008-08-02

PostSubject: Re: [Maths] Proving~~   Wed Sep 17, 2008 6:38 pm

Yup..you're rite Death..

Advice to Mia: y don't you diffrentiate ur ans bak..see if u get the ans anot?
Back to top Go down
View user profile
angie



Posts : 4
Join date : 2008-09-16

PostSubject: Re: [Maths] Proving~~   Wed Sep 24, 2008 10:45 pm

wakaka~~ let t= tan 1/2 x first~~ hehe~~ then start integrate the 1/sin x.... hehe Surprised flower
Back to top Go down
View user profile
withoutwax
Professor
Professor
avatar

Posts : 101
Join date : 2008-08-02

PostSubject: Re: [Maths] Proving~~   Thu Sep 25, 2008 11:06 am

wow..so geng?? try integrate the other one too..
Back to top Go down
View user profile
flamenix

avatar

Posts : 27
Join date : 2008-08-05

PostSubject: Re: [Maths] Proving~~   Sun Sep 28, 2008 12:14 am

I had done it.. A good question..
Back to top Go down
View user profile
Sponsored content




PostSubject: Re: [Maths] Proving~~   

Back to top Go down
 
[Maths] Proving~~
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» Proving bread in the HO oven
» Proving Dough
» The no name game
» L.O.L. = PROVING GROUNDS - TIME/TOURNAMENT
» Theory proven false: Do people see the same color differently?

Permissions in this forum:You cannot reply to topics in this forum
Mind Spirit Share :: Education Zone :: STPM-
Jump to: