Triangle inequality in Rubins book

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SUMMARY

The discussion centers on the triangle inequality as presented in Walter Rudin's book on complex analysis. The inequality states that for any complex numbers z and w, the relationship ||z|-|w|| ≤ |z-w| ≤ |z|+|w| holds true. A participant expresses confusion regarding the equality ||z|-|w|| = |z-w| using specific examples with z = -2 and w = 2. The conversation also touches on the interpretation of |z| as a length, as suggested by the definition provided in Rudin's text.

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  • Understanding of complex numbers and their properties
  • Familiarity with the triangle inequality in mathematics
  • Knowledge of Walter Rudin's definitions in complex analysis
  • Basic concepts of absolute value in the context of complex numbers
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  • Study the triangle inequality in detail, focusing on complex numbers
  • Review Walter Rudin's "Principles of Mathematical Analysis" for definitions and examples
  • Explore the geometric interpretation of complex numbers and their magnitudes
  • Practice problems involving complex inequalities to solidify understanding
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mynameisfunk
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My problem states:
Given z, w[tex]\in[/tex]C, prove: ||z|-|w||[tex]\leq[/tex]|z-w|[tex]\leq[/tex]|z|+|w|.

Now, I am confused because, isn't it true that ||z|-|w||=|z-w| ? I am using Rudin's book which gives |z|=([z's conjugate]z)1/2
 
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Take z =-2 and w = 2. Does ||z|-|w||=|z-w| still hold?
 
Ah. Thank you. Is it correct from the definition of |z| to think of it as a length? My gf is taking a complex variables class and she had told me that |z|= the length of z, but rudin's book gave the definition above, so i didn't know how to think about it.
 

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