Proving the Equivalence of √(1) and √(-1)(-1)

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SUMMARY

The discussion centers on the mathematical equivalence of √(1) and √(-1)(-1). The equation is analyzed through various transformations, ultimately leading to the conclusion that while √(1) = 1, the transformation involving complex numbers introduces complications. Specifically, the third equality, (√-1)(√-1) = i.i = i² = -1, is not universally valid without imposing specific conditions on the square root function. This highlights the nuances of squaring as a double-branched complex variable function.

PREREQUISITES
  • Understanding of complex numbers, specifically the imaginary unit i.
  • Familiarity with properties of square roots in both real and complex number systems.
  • Knowledge of mathematical functions and their branches, particularly in complex analysis.
  • Basic algebraic manipulation skills involving equations and identities.
NEXT STEPS
  • Study the properties of complex square roots and their implications in complex analysis.
  • Learn about the concept of branch cuts in complex functions.
  • Explore the implications of squaring functions in both real and complex domains.
  • Investigate the conditions under which certain mathematical identities hold true in complex analysis.
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Mathematicians, students of complex analysis, and anyone interested in the properties of square roots and complex numbers will benefit from this discussion.

Yh Hoo
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1 = √(1)
= √(-1)(-1)
= (√-1)(√-1)
= i.i
= i^{2}
= -1
Is this a correct equation??
anythings wrong with this?
i think theoretically it is correct but it seems like
√(1) = √(-1)(-1)
√(1) = √(1)(1) also!
so how to explain this??
 
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Yh Hoo said:
1 = √(1)
= √(-1)(-1)
= (√-1)(√-1)
= i.i
= i^{2}
= -1
Is this a correct equation??
anythings wrong with this?
i think theoretically it is correct but it seems like
√(1) = √(-1)(-1)
√(1) = √(1)(1) also!
so how to explain this??



Squaring is a double branched complex variable function, and thus "usual" properties in real numbers can fail miserably.

In this case the problem appears in the third equality: it isn't true without imposing certain restrictive conditions.

DonAntonio
 

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