I think I'm missing something in this complex number problem

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Discussion Overview

The discussion revolves around a complex number problem involving the evaluation of powers of -1 and their implications when multiplied by the imaginary unit i. Participants explore the differences in results produced by calculators and the importance of parentheses in mathematical expressions.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested, Homework-related

Main Points Raised

  • One participant questions the interpretation of -110 multiplied by i, noting a discrepancy in expected results.
  • Multiple participants assert that ##(-1)^{10} = 1##, while another participant expresses confusion over calculators returning -1 for similar expressions.
  • There is a discussion about the difference between ##-1^{10}## and ##(-1)^{10}##, with examples provided to illustrate how parentheses affect the outcome.
  • One participant explains that raising a power has higher precedence than multiplication, emphasizing the role of parentheses in clarifying calculations.
  • Another participant suggests that a lack of understanding of basic concepts may hinder progress in studies, recommending a return to foundational learning.
  • Advice is given to use parentheses in programming to ensure clarity in calculations.

Areas of Agreement / Disagreement

Participants generally agree on the mathematical principles regarding powers of -1, but there is disagreement on the interpretation of calculator outputs and the implications for understanding the problem.

Contextual Notes

Participants express confusion regarding calculator behavior and the precedence of operations, indicating a need for clarity on these foundational concepts. The discussion does not resolve the discrepancies in calculator outputs.

JR Sauerland
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As you can see, it says that -110 (-1 to the tenth is just -1), multiplied by i, is somehow i. Everywhere I have looked, -1 times i is negative i, but this problem disagrees. Am I missing something?
 

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##(-1)^{10} = 1##
 
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micromass said:
##(-1)^{10} = 1##

But how? Every calculator or form I put it into says it is -1...? EDIT: If I put -110 in my graphic calculator, it brings back -1. If I do it as (-1)10, it says 1. Witchcraft! I am so confused .:nb)
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There is a difference between ##-1^{10}##, which is apparently what the calculators are doing and ##(-1)^{10}##.
 
micromass said:
There is a difference between ##-1^{10}##, which is apparently what the calculators are doing and ##(-1)^{10}##.

What is the difference though?
 
For example:

[tex](-1)^4 = (-1)\cdot (-1)\cdot (-1)\cdot (-1) = 1[/tex]

while

[tex]-1^4 = - (1\cdot 1\cdot 1\cdot 1) = -1[/tex]
 
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micromass said:
For example:

[tex](-1)^4 = (-1)\cdot (-1)\cdot (-1)\cdot (-1) = 1[/tex]

while

[tex]-1^4 = - (1\cdot 1\cdot 1\cdot 1) = -1[/tex]

That was perfect! Thank you so much!
 
Raising a power by convention has higher precedence over multiplication just as multiplication has a higher precedence over addition. Parentheses allow you to reorder the precedence of operations. These rules are especially good to know when you start programming.
 
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JR you leep asking these questions that show that there are really basic things that you have not grasped. Your calculator does not give you the "right" answer because you do not know what buttons to press. If you do not know without even thinking about it that aný even power of -1 is equal to 1 then you cannot progress your studies. As you seem familiar with Khan Academy, can I suggest that you go RIGHT BACK TO THE BEGINNING and take every class?
 
Last edited:
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  • #10
Parentheses are your friends in programming. Use -(110) or (-1)10 to be sure what it is calculating exactly what you want it to.
 
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