Finding polar and cartesian form for this power

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Homework Help Overview

The discussion revolves around finding the polar and Cartesian forms of the complex expression \((-1+i)/(√2)\) raised to the power of 1002. The subject area includes complex numbers, polar coordinates, and exponential forms.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the calculation of the modulus and argument of the complex number, with initial attempts to find the argument leading to confusion over its correct value. There are questions about the implications of the angle in relation to the quadrant and how to simplify the expression after raising it to the power of 1002.

Discussion Status

Participants are actively engaging with the problem, questioning each other's calculations and assumptions regarding the argument of the complex number. Some guidance has been offered regarding the correct angle and the need to consider the power in the final expression, but no consensus has been reached on the final form.

Contextual Notes

There is an ongoing discussion about the correct value of the argument and the implications of raising the complex number to a power, with some participants noting potential errors in earlier calculations.

charmedbeauty
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Homework Statement



((-1+i)/(√2))^1002
find polar and cartesian form

Homework Equations





The Attempt at a Solution




So I started by finding |z|=1

and Arg(z)= arctan (-1) = 5pi/6

so 1^(1002)*e^(i*5pi/6)*1002 =1*e^(i*835pi)

but that's as far as I got because the answer says -i, but to get that term I need 1*e^-ipi/2

any thoughts??
 
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Your main problem is that [itex]arctan(-1)[/itex] is NOT [itex]5\pi/6[/itex]!

Calculate that again.
 
HallsofIvy said:
Your main problem is that [itex]arctan(-1)[/itex] is NOT [itex]5\pi/6[/itex]!

Calculate that again.

I was assuming since the original eqn has a negative real part then I would add Pi/2 since the angle is measured from 0.
Although I am getting 3pi/4 now
 
Well, yes (3pi)/4 is the angle you're looking for since this is in the second quadrant.

You have got |z|, and now you have the angle.

Put it into exponential form to the power of 1002, and simplify it to get the angle in terms of a principal argument.
 
NewtonianAlch said:
Well, yes (3pi)/4 is the angle you're looking for since this is in the second quadrant.

You have got |z|, and now you have the angle.

Put it into exponential form to the power of 1002, and simplify it to get the angle in terms of a principal argument.

Ok so now I have 1^1002*(cos 3Pi/4+isin3Pi/4)

= 1*(0)=0 how do they get the minus i?
 
charmedbeauty said:
Ok so now I have 1^1002*(cos 3Pi/4+isin3Pi/4)

= 1*(0)=0 how do they get the minus i?

How did you get 0 for (cos 3Pi/4 + isin 3Pi/4) ?

Also, you have forgotten to raise that to the power.
 
NewtonianAlch said:
How did you get 0 for (cos 3Pi/4 + isin 3Pi/4) ?

Also, you have forgotten to raise that to the power.

isnt cos 3pi/4=-0.7...

and sin 3pi/4=0.7...
 
charmedbeauty said:
isnt cos 3pi/4=-0.7...

and sin 3pi/4=0.7...

Yes, but you have a complex number there.

-0.707 +0.707i

You can't add them just like that.

What of the 1002? You need to account for that too.
 

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