ATAR Notes: Forum

HSC Stuff => HSC Maths Stuff => HSC Subjects + Help => HSC Mathematics Extension 2 => Topic started by: frog1944 on April 29, 2017, 03:12:40 pm

Title: Integration by Parts Method
Post by: frog1944 on April 29, 2017, 03:12:40 pm
Hi,

When evaluating an integral using integration by parts, is it required for you to write, u = ..., dv = .... etc. Or can you do that in your head or just jot it down on the side of the page in a less formal manner?

Thanks
Title: Re: Integration by Parts Method
Post by: jakesilove on April 29, 2017, 03:45:28 pm
Hi,

When evaluating an integral using integration by parts, is it required for you to write, u = ..., dv = .... etc. Or can you do that in your head or just jot it down on the side of the page in a less formal manner?

Thanks

Whilst I don't think it's required that you write out that information, I would strongly recommend that you do. If you do it in your head, you're more likely to make a mistake. Alternatively, if you do mess up your calculation somewhere, you're more likely to receive working marks if you've shown the correct steps. I get that writing out the integration by parts method can be tedious, especially when you've done the same integral so many times. However, I would seriously recommend getting into the habit of doing it everytime!
Title: Re: Integration by Parts Method
Post by: RuiAce on April 29, 2017, 04:10:06 pm
Personally I stopped writing it out after just doing about a week of them.

But I've seen a ton of scenarios where people mess up doing it inside their head. So do whatever you feel is safest for you.
Title: Re: Integration by Parts Method
Post by: frog1944 on April 30, 2017, 07:05:20 am
Ok, thanks guys :)
Title: Re: Integration by Parts Method
Post by: jamonwindeyer on April 30, 2017, 10:31:16 am
Personally I stopped writing it out after just doing about a week of them.

But I've seen a ton of scenarios where people mess up doing it inside their head. So do whatever you feel is safest for you.

I still mess it up doing it in my head in third year lol
Title: Re: Integration by Parts Method
Post by: GodlyOne on April 30, 2017, 10:39:35 am
Im pretty sure you would get marks too if you wrote it down.
Title: Re: Integration by Parts Method
Post by: RuiAce on April 30, 2017, 10:43:23 am
I still mess it up doing it in my head in third year lol
Ouch...

But yeah, I never wrote my u's and dv's. And I always got marks for it.