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Complex Numbers Help (1 Viewer)

untouchablecuz

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Why does:

|iz| = |i||z| = |z|

or

|bz| = |b||z| = |z|

What happens to |i| or |b| at the end?

Thanks for any help (I just started 4 unit today).
 

gurmies

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|zi| = |z||i|
= |z|
I have also recently started 4 unit, so my explanation may be dodgy and at worst, wrong. Not sure why at this particular point in time, but you know that |z1| x |z2| = |z1z2|. In words, the modulus of a complex number multiplied by the modulus of another complex number is equal to the modulus of the products of these complex numbers. Anyway assume z is any complex number x + iy. You know that in the case of "i" x = 0 and y = 1. Therefore it's modulus is 1. So in essence, you are writing 1 x |z| = |z|. As for the b, not sure what's going on there? Logically the modulus of b has to be 1.
 
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tabbaa

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Hey OP

When you multiply an complex number with i, it just means that you are rotating it 90 deg anti-clockwise.

The Mod doesn't change.
 

shaon0

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Hey guys,
I've proved this but have seemingly lost where i wrote the solution.
z=a+ib
Prove:
If (z)/(z-i) is real then z is imaginary.
 

shaon0

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shaon0 said:
Hey guys,
I've proved this but have seemingly lost where i wrote the solution.
z=a+ib
Prove:
If (z)/(z-i) is real then z is imaginary.
Anyone?
 

untouchablecuz

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shaon0 said:
Hey guys,
I've proved this but have seemingly lost where i wrote the solution.
z=a+ib
Prove:
If (z)/(z-i) is real then z is imaginary.
Scroll down to find it. :)
 

Cazic

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Hahaha, I was like wtf is untouchablecuz asking this for?
 

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