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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Specialist Mathematics => Topic started by: lisafaustina on October 07, 2010, 02:38:04 pm

Title: Complex plane
Post by: lisafaustina on October 07, 2010, 02:38:04 pm
you know when you have to draw like a circle and a ray on an argand diagram ? well how do you find the point where the line and the circle meet and the area and such, cos those type of questions come up on the exams pretty frequently but theyre not in the book so i have no idea what to do.
Title: Re: Complex plane
Post by: 98.40_for_sure on October 07, 2010, 03:24:11 pm
What do you mean a circle and a ray? i'm not exactly sure what you're asking, however im guessing you're referring to those ones where you have to divide the area up and calculate separate bits
Title: Re: Complex plane
Post by: jasoN- on October 07, 2010, 03:42:16 pm
I think she means a circle and a line intersecting it
eg. |z|<2 (intersect sign) |z|=|z-3+i|
find the equation of the line and the circle, then rearrange to get the intersect
if it's tech free i don't think they would ask for the intersection between the line and the circle
for tech active, simply use solve function in calc
Title: Re: Complex plane
Post by: fady_22 on October 07, 2010, 06:40:54 pm
To find the area, don't start thinking "I have to integrate this somehow!". Most of the time, you can find the area using the formula for a sector of a circle. :)
Title: Re: Complex plane
Post by: lisafaustina on October 07, 2010, 08:52:13 pm
Ooh how ?
Title: Re: Complex plane
Post by: Chavi on October 07, 2010, 08:58:35 pm
sector: 1/2 theta r^2 where theta is in radians
segment: 1/2 r^2 (sin(theta) - theta)