ATAR Notes: Forum

VCE Stuff => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematics => Topic started by: /0 on October 17, 2009, 11:38:01 pm

Title: calculator grief
Post by: /0 on October 17, 2009, 11:38:01 pm: When I integrate $\int \frac{1}{x-1}$ , I get $\ln(x-1)$ ... is this happening to anyone else?

(Technically $\ln|x-1|$ )
Title: Re: calculator grief
Post by: Flaming_Arrow on October 17, 2009, 11:41:30 pm: err isn't that meant to be the answer?
Title: Re: calculator grief
Post by: /0 on October 17, 2009, 11:42:19 pm: sorry i edited my post

It's really annoying because sometimes you have something that should be $\ln(1-x)$ but your calculator spits out $\ln(x-1)$ . Especially in complicated integrations where you have to go and change each term manually. At least $\ln|x-1|$ isn't blatantly wrong.
Title: Re: calculator grief
Post by: dekoyl on October 17, 2009, 11:43:45 pm: On the Ti-89T, I get $\ln(|x-1|)$ .
Title: Re: calculator grief
Post by: /0 on October 17, 2009, 11:44:29 pm: What version is your calculator? I have 3.10, is that old?
Title: Re: calculator grief
Post by: dekoyl on October 17, 2009, 11:47:00 pm: Mine is 3.10 as well. I think Mao has the same version.
Title: Re: calculator grief
Post by: cobby on October 18, 2009, 08:20:18 am: I got $\ln(|x-1|)$ too, using Ti-89T, 3.10
Title: Re: calculator grief
Post by: TonyHem on October 18, 2009, 08:46:48 am: I get it with the modulus sign too.
How do you check what version you have?
Title: Re: calculator grief
Post by: cobby on October 18, 2009, 08:56:54 am: Quote from: TonyHem on October 18, 2009, 08:46:48 am
I get it with the modulus sign too.
How do you check what version you have?
Press F1 in the Home screen, then scroll down to 'About' and it should say OS Version at the top.
Title: Re: calculator grief
Post by: /0 on October 18, 2009, 04:57:54 pm: That's weird :/
Title: Re: calculator grief
Post by: TrueTears on October 18, 2009, 04:59:27 pm: I get mod signs as well? Maybe get your calc at school and link cable and I can send you over my OS or something.