Complex numbers question

[Jared123]

Im having problems with this question

Consider a complex number ? = ? + ?? where ? and ? are real. Evaluate |???(??) + ??(?)| .


My understanding of complex numbers is only moderate and an explanation on how to answer this would be much appreciated

 

[Deleted member 4993]

Im having problems with this question

Consider a complex number ? = ? + ?? where ? and ? are real. Evaluate |???(??) + ??(?)| .


My understanding of complex numbers is only moderate and an explanation on how to answer this would be much appreciated

First you'll need to calculate iz = ? (given z = a + i b)

Then you will need calculate (from above) Re(iz)

and continue.....

 

[Steven G]

a is the real part, denoted by Re(z) and b is the imaginary part of z, denoted by im(z).

To find iRe(iZ) we have to multiply i by Re(iz). Before we can find Re(iZ) we need to find iZ. How do you find iZ? You multiply Z by i.

See what you can do with that.

 

[pka]

a is the real part, denoted by Re(z) and ib is the imaginary part of z, denoted by im(z).
To find iRe(iZ) we have to multiply i by Re(iz). Before we can find Re(iZ) we need to find iZ. How do you find iZ? You multiply Z by i.

Actually if \(z=a+bi\) then \(\Im(z)=b\). Both functions \(\Re~\&~\Im\) are real valued.

 

[Steven G]

Actually if \(z=a+bi\) then \(\Im(z)=b\). Both functions \(\Re~\&~\Im\) are real valued.

Thanks, I was wondering about that. I should have looked that up before posting!

 

[Jared123]

First you'll need to calculate iz = ? (given z = a + i b)

Then you will need calculate (from above) Re(iz)

and continue.....

This is what I got for my answer. Is this correct

 

[Jared123]

a is the real part, denoted by Re(z) and b is the imaginary part of z, denoted by im(z).

To find iRe(iZ) we have to multiply i by Re(iz). Before we can find Re(iZ) we need to find iZ. How do you find iZ? You multiply Z by i.

See what you can do with that.

Is this the right way?

 

[Steven G]

Let z = a + bi where and b are real numbers

You wrote i(Re(-b)) + Im(b) = 2b^2 ?????

Re(-b) = -b, so iRe(-b))=-bi
Im(b) = Im (b+0i)=0
So iRe(-b) + Im (b) = -bi. How did you arrive at 2b^2 and why are you calculating magnitudes??

Besides you were asked to find |iRe(iz) + Im(z)| !!