Proof of complex number identity

In summary, the conversation is about a question involving the identity arg zw = arg z + arg w and using it to show the truth of arg z^n = n arg z. The first part of the question is more challenging and the second part builds upon the first part. The conversation also discusses the base case and the inductive case, with a hint provided for the latter.
  • #1
Gameowner
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Homework Statement



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Homework Equations





The Attempt at a Solution



The second part of question is relatively easy, it is the first part of the question where I need help with(using arg zw = arg z + arg w to show arg z^n = n arg z).

Also, is the question asking to proof de Moivre's formula with the identity arg zw = arg z + arg w? or just proof LHS=RHS?
 

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  • #2
I guess it's the induction that's causing problems. Show that it's true for z2. Then show that if it's true for zn, that it's also true for zn+1.

The second part uses the relation you proved in the first part.
 
  • #3
The base case would be for z1, I thought. In any event, it's easy to prove.
The inductive case: assume true for n = k, show that it's true for n = k + 1.
Here's a hint: xa + 1= (xa)(x).69
 

Related to Proof of complex number identity

What is "Proof of complex number identity"?

"Proof of complex number identity" refers to the process of demonstrating that two complex numbers are equal by showing that their real and imaginary components are equal.

Why is proving complex number identity important?

Proving complex number identity is important because it allows us to verify the accuracy and validity of mathematical equations and calculations involving complex numbers. It also helps us to better understand the properties of complex numbers.

What is the general method for proving complex number identity?

The general method for proving complex number identity is to separate the given complex numbers into their real and imaginary components, and then equate each component to show that they are equal.

Are there any special cases or exceptions when proving complex number identity?

Yes, there are some special cases and exceptions when proving complex number identity, such as when one or both of the complex numbers have a coefficient of 0 or when the complex numbers are in polar form.

Can you provide an example of a proof of complex number identity?

Sure, for example, to prove that (2+3i)+(4-5i)=6-2i, we can separate each complex number into its real and imaginary components: 2+3i can be written as (2+0i)+(0+3i), and 4-5i can be written as (4+0i)+(0-5i). Then, we can equate the real and imaginary components separately: (2+0i)+(4+0i)=6+0i, and (0+3i)+(0-5i)=0-2i. Finally, we combine the real and imaginary components to show that (2+3i)+(4-5i)=6-2i, thus proving the complex number identity.

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