Respuesta :
The difference cos(120° - 45°) is most likely the form you would use with that formula.
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The "difference" cos(30° + 45°) could also be used, where 45° is rewritten as -(-45°), or 30° is rewritten as -(-30°).
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The "difference" cos(30° + 45°) could also be used, where 45° is rewritten as -(-45°), or 30° is rewritten as -(-30°).