Sine of Complement equals Cosine/Examples/2 Theta minus 90

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Example of Sine of Complement equals Cosine

$\map \sin {2 \theta - 90 \degrees} = -\cos 2 \theta$


Proof

\(\ds \map \sin {2 \theta - 90 \degrees}\) \(=\) \(\ds -\map \sin {90 \degrees - 2 \theta}\) Sine Function is Odd
\(\ds \) \(=\) \(\ds -\cos 2 \theta\) Sine of Complement equals Cosine

$\blacksquare$


Sources