HSC 2016 MX2 Integration Marathon (archive) (1 Viewer)

[leehuan]

Re: MX2 2016 Integration Marathon

Can someone like just... Point out my mistake already...


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[Paradoxica]

Re: MX2 2016 Integration Marathon

Can someone like just... Point out my mistake already...


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Go back to before you used a trigonometric substitution. Try something else. Technically, your t substitution will work, but I'd rather not go through three different substitutions.

 

[leehuan]

Re: MX2 2016 Integration Marathon

Go back to before you used a trigonometric substitution. Try something else. Technically, your t substitution will work, but I'd rather not go through three different substitutions.

I got lost right after my first instinct of s^2=u^2+...

Not sure what else to use actually. s=u+2 felt like it was doing nothing.

 

[Paradoxica]

Re: MX2 2016 Integration Marathon

I got lost right after my first instinct of s^2=u^2+...

Not sure what else to use actually. s=u+2 felt like it was doing nothing.

Have you tried by parts?

 

[leehuan]

Re: MX2 2016 Integration Marathon

Have you tried by parts?

No idea at all what to integrate in IBP. :/

edit: ......

 

[Paradoxica]

Re: MX2 2016 Integration Marathon

No idea at all what to integrate in IBP. :/

edit: ......

I can interpret that as you just found out the answer so very quickly, or you tried by parts and got you nowhere. Please collapse the wavefunction.

 

[leehuan]

Re: MX2 2016 Integration Marathon

I can interpret that as you just found out the answer so very quickly, or you tried by parts and got you nowhere. Please collapse the wavefunction.

Lol I thought I had an epiphany but nope.

Edit: >_>.....or did I

 

[leehuan]

Re: MX2 2016 Integration Marathon

Screw it lol. Someone put me out of my agony I can't integrate today.

 

[JusticeTackle]

Re: MX2 2016 Integration Marathon

Have you tried by parts?

Are you sure that there exists a nice elementary primitive? Check wherever you got this question from.

If so, post it. If you don't, it's safe to assume that you're just trying to waste our times with a question that cannot be done.

So please post the expression


Thanks, Mumen Rider

P.S When this was posted, you were browsing this thread.

 

[Paradoxica]

Re: MX2 2016 Integration Marathon

Screw it lol. Someone put me out of my agony I can't integrate today.

Hmm... It seems the answer is not as nice as I had anticipated... This may take some time.

 

[Paradoxica]

Re: MX2 2016 Integration Marathon

Are you sure that there exists a nice elementary primitive? Check wherever you got this question from.

If so, post it. If you don't, it's safe to assume that you're just trying to waste our times with a question that cannot be done.

So please post the expression


Thanks, Mumen Rider

P.S When this was posted, you were browsing this thread.

Yes, an elementary form exists. Three logs and a square root.

 

[InteGrand]

Re: MX2 2016 Integration Marathon

Hmm... It seems the answer is not as nice as I had anticipated... This may take some time.

And to compound matters, LaTeX doesn't seem to be working on the site right now.
Test:

 

[glittergal96]

Re: MX2 2016 Integration Marathon

Yeah, I would probably just resort to t-substitution after reaching the trig form of sec^3(s)/(1+tan(s)).

You are guaranteed success, it's just not an interesting / enlightening process.

I briefly tried some other things like the analogous hyperbolic trig route instead, but couldn't see anything nicer.

 

[leehuan]

Re: MX2 2016 Integration Marathon

If only the original integrand just had 3x^2. That would've made it a lot easier.

 

[Paradoxica]

Re: MX2 2016 Integration Marathon

Yeah, I would probably just resort to t-substitution after reaching the trig form of sec^3(s)/(1+tan(s)).

You are guaranteed success, it's just not an interesting / enlightening process.

I briefly tried some other things like the analogous hyperbolic trig route instead, but couldn't see anything nicer.

I've got a solution that involves introducing the t substitution later. I'm typing it up but I can't even know if my typesetting is correct because codecogs servers are down.

 

[Paradoxica]

Re: MX2 2016 Integration Marathon

If only the original integrand just had 3x^2. That would've made it a lot easier.

Yeah keep dreaming m9

 

[leehuan]

Re: MX2 2016 Integration Marathon

Yeah keep dreaming m9

Pls I can do what I want.

 

[leehuan]

MX2 2016 Integration Marathon

I thought about this just now


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Edit: fraction should be +2

 

[glittergal96]

Re: MX2 2016 Integration Marathon

I've got a solution that involves introducing the t substitution later. I'm typing it up but I can't even know if my typesetting is correct because codecogs servers are down.

Yeah, there are a few different ways / times to do it. I don't think any of them will be significantly faster than all of the others though, its pretty much preference.

 

[glittergal96]

Re: MX2 2016 Integration Marathon

I thought about this just now


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Edit: fraction should be +2

oh nice, yeah that will do it .