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**BLANK****Guest**

Prove that if w,z are complex numbers such that |w|=|z|=1 and wz!= -1, then (w+z)/(1+wz) is a real number.

**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,386

hi BLANK,

Welcome to the forum.

I think this has been asked before and fairly recently but I haven't managed to find it yet. You have typed

wz!= -1

which seems like a typo. ! would be 'factorial' and that makes no sense in this context. If we drop the ! then wz = -1 and that also makes no sense as it makes the denominator of the expression zero.

Please respond with a clarification.

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,386

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**dogleg****Member**- Registered: 2018-04-20
- Posts: 1

Hi. I am new to this forum and very rusty in my math. I am trying to relearn roots of expressions like : Square root of x-3 = , and fourth root of x-3 for example. Help me get started please.

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,386

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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