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Specialist Mathematics Β· Unit 3 Β· Further complex numbers Β· Complex arithmetic using polar form

Prove complex number identities involving modulus and argument, e.g. 𝑧 𝑧̅ = |𝑧|2, |𝑧1| |𝑧2| = |𝑧1 𝑧2| and arg(𝑧1 𝑧2) = arg(𝑧1) + arg(𝑧2).

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Question 1

Given \(z \in \mathbb{C}\), where \(z \neq 0\), prove \(|z^2| = |z|^2\).

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Question 2

A complex number \(z = x + yi\), where \(x, y \in \mathbb{R}\) and \(z \neq 0\), is shown on the Argand diagram. Prove that \(|z^2| = |z|^2\).

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