Modulus of a Complex Number Question

tylerc1991
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Homework Statement



My prof was saying today that the modulus of a complex number isn't the absolute value. The problem is the following:

Graph the set of points satisfying the following equation(s):

|z-1+i|=1

The Attempt at a Solution



Can I not just say that z = -i or z = 2-i and hence the graph is just two points? Or is this the correct answer?
 
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If you plot |z-1+i|=1 on an argand digram, you will see that this does not give only two solutions. If you put z=x+iy into the equation and then find the modulus knowing that |a+ib|=√(a2+b2), what do you get?
 
I see what I did wrong now. If I let z = x + iy I am getting:

(x-1)^2 + (y+1)^2 = 1, which is obviously a circle.

Thanks!
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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