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Prove that b^(2) cos 2 A - a^(2) cos 2B ...

Prove that `b^(2) cos 2 A - a^(2) cos 2B = b^(2) -a^(2)`

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To prove the equation \( b^2 \cos 2A - a^2 \cos 2B = b^2 - a^2 \), we will follow these steps: ### Step 1: Use the double angle identities for cosine We know that: \[ \cos 2A = 1 - 2\sin^2 A \quad \text{and} \quad \cos 2B = 1 - 2\sin^2 B \] Substituting these identities into the equation gives: ...
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