+0  
 
0
679
4
avatar

please help

determine M(z) as : z is a complex nember and

/z/=z+conjugated(z)

NOTE:

(/z/=module of z)

 Mar 14, 2015

Best Answer 

 #4
avatar+118677 
+5

Thanks Shaomada, you are ofcourse correct.  The question just confused me.

when I said that    $$|z|\ne z+\bar z$$    I really meant that they are not the same thing.

You are right - they are equal sometimes.

 

$$\\\sqrt{a^2+b^2}=2a\qquad a \ge 0\\
a^2+b^2=4a^2\\
b^2=3a^2$$

 

They will be equal whenever this condition is met.

 Mar 16, 2015
 #1
avatar+118677 
0

I do not understand this question so I am just going to prattle about it.

 

$$\\if\;\;z=a+bi\\\\
\mbox{Then conjugate of z }=\bar z = a-bi\\\\
and\\\\
|z|=|\bar z|=\sqrt{a^2+b^2}\\\\
|z|$ is the distance of z from the origin in the complex number plane
$\\\\
|z|$ is the modulus of z$\\\\
|z| \ne z+\bar z\\\\
z+\bar z=a+bi+a-bi = 2a\\\\
$Hence I am confused $$$

 Mar 15, 2015
 #2
avatar
0

how about : 0.5/z/=z+conjugated(z)

 

thanks a lot anyway

 Mar 15, 2015
 #3
avatar+66 
+5

Shouldnt exactly the complex numbers of the form $$z=a+i\cdot b$$ for which $$\lvert b \rvert = \sqrt{3} \cdot a$$ fullfill this? You want $$\sqrt{a^2+b^2} = \lvert z \rvert = z + \overline{z} = (a + i \cdot b) + (a - i \cdot b) = 2 \cdot a = \sqrt{4a^2}$$. If we assume $$a$$ to be not negative this is equivalent to $$a^2 + b^2 = 4a^2$$ or to $$b^2 = 3 \cdot a^2$$.

Also Melody, i don't get why $$\lvert z \rvert \neq z + \overline{z}$$ should hold for all complex numbers $$z$$.

 Mar 15, 2015
 #4
avatar+118677 
+5
Best Answer

Thanks Shaomada, you are ofcourse correct.  The question just confused me.

when I said that    $$|z|\ne z+\bar z$$    I really meant that they are not the same thing.

You are right - they are equal sometimes.

 

$$\\\sqrt{a^2+b^2}=2a\qquad a \ge 0\\
a^2+b^2=4a^2\\
b^2=3a^2$$

 

They will be equal whenever this condition is met.

Melody Mar 16, 2015

1 Online Users

avatar