• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

Complex Locus (1 Viewer)

shaon0

...
Joined
Mar 26, 2008
Messages
2,029
Location
Guess
Gender
Male
HSC
2009
1) Sketch: arg(z-(1+i)) = arg(z-(-2+5i))
Is it just the line via the points excluding the points.

2) Sketch: arg(z-(1+i)) = arg(1-(-2+5i))+pi

3) Sketch: arg(z+3-i) = arg(z-(2-i))

Just need some tips at drawing complex locus.
 

kaz1

et tu
Joined
Mar 6, 2007
Messages
6,960
Location
Vespucci Beach
Gender
Undisclosed
HSC
2009
Uni Grad
2018
I think 1 and and 3 are 2 lines moving away from each other and 2 is a most of a circle with the complex numbers as a chord which is the boundary of the circle.
 
Last edited:

Harkaraj

Member
Joined
Apr 8, 2006
Messages
117
Location
Sydney
Gender
Male
HSC
2008
Uni Grad
2013
1 and 3 is perpendicular bisectors of two points and 2 is the locus of an arc on a circle (explained well in cambridge/patel).
 

kaz1

et tu
Joined
Mar 6, 2007
Messages
6,960
Location
Vespucci Beach
Gender
Undisclosed
HSC
2009
Uni Grad
2018
Harkaraj said:
1 and 3 is perpendicular bisectors of two points and 2 is the locus of an arc on a circle (explained well in cambridge/patel).
Don't you get perpendicular bisectors when the modulus is equal?
 

cyl123

Member
Joined
Dec 17, 2005
Messages
95
Location
N/A
Gender
Male
HSC
2007
1) line through both 1+i and -2+5i EXCLUDING the points AND the section in between the points.

3) is similar to 1)

2) Note: if the locus is an arc of the circle, that means the angle of the circumference will be pi LOL which is impossible. Rather, the locus is just the interval joining the 2 points 1+i and -2+5i EXCLUDING the 2 points (which is section excluded in part 1)

To get each of these locuses, its easier to visualise them geometrically. You just plot the 2 points (eg in 1) 1+i and -2+5i) firstly and just think where z must lie in order for vector formed with each point and z to be pointing in same direction (ie same argument). BE CAREFUL cos direction of vectors do matter and for points lying between 1+i and -2+5i, the directions of the 2 vectors formed with z and the 2 points respectively with be in opposite direction (satisfying the second question's condition)
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top