Complex numbers, find (3/(1-i)-(1-i)/2)^40?

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Homework Help Overview

The discussion revolves around evaluating the expression (3/(1-i)-(1-i)/2)^40, which involves complex numbers. Participants are exploring the simplification and computation of this expression, particularly using polar form and de Moivre's theorem.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the conversion of the complex number (1 + 2i) into polar form and the application of de Moivre's theorem for raising it to the 40th power. There are questions about the correctness of the initial results and concerns about the complexity of manual calculations.

Discussion Status

Some participants have confirmed similar results, while others express uncertainty about the accuracy of their computations. There is a suggestion that the problem may have been copied incorrectly, which could affect the approach taken. The discussion is ongoing with various interpretations being explored.

Contextual Notes

Participants mention the complexity of calculations by hand and the potential for errors in the problem statement itself, which may impact their approaches and results.

iamavisitor
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Homework Statement



Please help me find (3/(1-i)-(1-i)/2)^40. I got a result (see below) but I'm not sure whether it is correct. Any help is appreciated. Thanks.

Homework Equations





The Attempt at a Solution



I got (1+2i)^40. After this I got some funny numbers like 7^10*16*(6232-474*i).
 
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iamavisitor said:

Homework Statement



Please help me find (3/(1-i)-(1-i)/2)^40. I got a result (see below) but I'm not sure whether it is correct. Any help is appreciated. Thanks.

Homework Equations





The Attempt at a Solution



I got (1+2i)^40.
I get this (above) also.
iamavisitor said:
After this I got some funny numbers like 7^10*16*(6232-474*i).
The way to go here is to convert 1 + 2i into polar form, using the Theorem of de Moivre. Then raising to the 40th power is easy.
See http://en.wikipedia.org/wiki/De_Moivre's_formula.
 
I know about de Moivre's formula. With it I get radius (r) to be sqrt(5) and angle 63.43 degrees. Again this is complicated to do by hand and I am wandering whether I got something wrong.
 
It is correct. But it might be that you or somebody else copied the problem wrong. (3/(1-i)-(1+i)/2)^40 would be easy.

ehild
 
iamavisitor said:
I know about de Moivre's formula. With it I get radius (r) to be sqrt(5) and angle 63.43 degrees. Again this is complicated to do by hand and I am wandering whether I got something wrong.
No, it's not complicated to do by hand once you have the complex number in this form.

[r*e]n = rn*eniθ
 

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