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naav
Jun27-04, 08:58 PM
Hi...i was wondering if someone could confirm if what i have below is correct...thanks...sorry i can't present a diagram...

z(1) = x + iy and z(2) = x(2) + iy(2) are represented by the vectors OP and OQ on an argand diagram...(O is the origin)...imagine the argand diagram...the upper left hand quadrant...(OQ has an argument of say 30 degrees and OP has an argument of 45 degrees - these pieces of information are not relevant anyway)...

is the following correct...

vector OP + vector PQ = vector OQ...

then vector PQ = vector OQ - vector OP

then vector PQ = |z(2) - z(1)|...

1. was wondering if my notation and understanding here is correct...i used algebra in the second line so i was wondering if that is legit...???...

2. is it correct to say in the last line the vector = the magnitude...

AKG
Jun27-04, 10:40 PM
1. was wondering if my notation and understanding here is correct...i used algebra in the second line so i was wondering if that is legit...???...That's fine.
2. is it correct to say in the last line the vector = the magnitudeThat's wrong. You should have:

\vec{PQ} = z_2 - z_1

|\vec{PQ}| = |z_2 - z_1|

Or, in plain text:

vector PQ = z(2) - z(1)
|vector PQ| = |z(2) - z(1)|

naav
Jun28-04, 05:40 AM
Hi...thank you very much...

i said in my earlier post...

then vector PQ = |z(2) - z(1)|...

and it was said that it should be...

|vector PQ| = |z(2) - z(1)|

1. isn't that the same thing...

that vector PQ = the magnitude of [z(2) - z(1)]...???...

HallsofIvy
Jun28-04, 06:28 AM
No, it is not the same thing: |vector PQ| is a number (the length of the vector PQ), not a vector.

Likewise "vector PQ" is a vector while "the magnitude of [z(2)-z(1)]" is a number.

naav
Jun28-04, 10:54 AM
thank you very much...