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# Fp2 Complex Numbers question watch

1. Hi,

http://pmt.physicsandmathstutor.com/...%20Edexcel.pdf

On Q6 on the link above, I got up to the point where:
3|w-1| = |wi|

I don't understand why it is valid to cancel the i on the right hand side as the author of the model answers has done, and feel as though I have a gap in my knowledge.
I'm aware leaving the i in will lead to some difficulty later on, but I can't work out why it is valid to just remove it.

2. Standard rule |Z1 x Z2| = |Z1| x |Z2|

|wi| = |w| x |i| = |w|
3. (Original post by JLegion)
Hi,

http://pmt.physicsandmathstutor.com/...%20Edexcel.pdf

On Q6 on the link above, I got up to the point where:
3|w-1| = |wi|

I don't understand why it is valid to cancel the i on the right hand side as the author of the model answers has done, and feel as though I have a gap in my knowledge.
I'm aware leaving the i in will lead to some difficulty later on, but I can't work out why it is valid to just remove it.

4. (Original post by JLegion)
Hi,

http://pmt.physicsandmathstutor.com/...%20Edexcel.pdf

On Q6 on the link above, I got up to the point where:
3|w-1| = |wi|

I don't understand why it is valid to cancel the i on the right hand side as the author of the model answers has done, and feel as though I have a gap in my knowledge.
I'm aware leaving the i in will lead to some difficulty later on, but I can't work out why it is valid to just remove it.

it could have been shown using another step , but I guess he just wanted to safe space.
5. Thank you everyone for the swift replies.

I feel stupid not to know that; although in my defence my text book doesn't mention it once! ^.^

Thanks again.

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