locus question (1 Viewer)

[lum]

hey, dunno how to do this, can someone help?

|z-3| = |z-2||z-i|

thx

 

[Sepulchres]

I tried it. Have a look.

 

[adzy]

What would that look like on cartesian graph?

 

[Sepulchres]

What would that look like on cartesian graph?

G'luck working that out.

 

[shafqat]

The locus where the product of distances from two points is a constant is a Cassini's oval, but what the hell is that?

 

[Sepulchres]

Im probably wrong, I just tried it, simplified it, and tried to factorise it. Thats what came out. = \

 

[who_loves_maths]

everything is ok with your expansion except for, ironically, the constant.
it should be -5, not 13.

 

[lum]

The locus where the product of distances from two points is a constant is a Cassini's oval, but what the hell is that?

cassini's oval??? wth is that?? and the qs asked for a description of the locus, not a sketch, how do u describe it?

 

[turtle_2468]

the lazy answer: I'm pretty sure this isn't in the HSC syllabus
There are programmes which curveplot for you.. hang on, I have one of those.. too late. I'll try tomorrow if someone reminds me

 

[martin]

Not to steal Turtle's thunder or anything but I'm sure he won't mind. In Matlab I just put in

>> ezplot('(x-3)^2+y^2-((x-2)^2+y^2)*(x^2+(y-1)^2)',[-3,3],[-1,3])
>> hold on
>> plot([3 2 0],[0 0 1],'rx')

and get the attached graph. I don't think its any easily describable curve.

 

[Sepulchres]

Not to steal Turtle's thunder or anything but I'm sure he won't mind. In Matlab I just put in

>> ezplot('(x-3)^2+y^2-((x-2)^2+y^2)*(x^2+(y-1)^2)',[-3,3],[-1,3])
>> hold on
>> plot([3 2 0],[0 0 1],'rx')

and get the attached graph. I don't think its any easily describable curve.

Wow.

10 characters

 

[blackfriday]

there was actually two parts before that question, part (i) was find the square roots of some complex number, which turned out to be the discriminant of part (ii) quadratic equation and part (iii) was the question my mate lum gave you. i dont think you are meant to know cassini's oval because you are given two parts before that.