ATAR Notes: Forum

VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Specialist Mathematics => Topic started by: Chavi on October 29, 2010, 03:30:24 pm

Title: Arg(z)
Post by: Chavi on October 29, 2010, 03:30:24 pm: Is the base line (i.e. Argz=0 included when sketching arg graphs?

For example, on M.C. question 9 from Itute 2009:
http://www.itute.com/wp-content/uploads/2008-specialist-mathematics-trial-exam-2.pdf

I thought the answer was B, because 0 is not included, but it turns out that it's A, with 0 included, just not graphed. . .
Why is this?
Title: Re: Arg(z)
Post by: 98.40_for_sure on October 29, 2010, 03:35:17 pm: The solution is saying everything in the complex field excluding... and 0 is excluded? Not sure exactly what it is you're asking.

EDIT: the white bit is $0\leq Arg(z+1+\sqrt{3}i)< \frac{2\pi }{3}$
so therefore the shaded bit is everything that isn't that, so
C \ $0\leq Arg(z+1+\sqrt{3}i)< \frac{2\pi }{3}$
Title: Re: Arg(z)
Post by: Chavi on October 29, 2010, 03:50:01 pm: Ah. Missed out the "excluding" part. Thanks +1