Write the given expression as the cosine of an angle. 
Definitions:
Transactional Messages
Communications focused on facilitating, completing, or confirming a commercial transaction.
Encoded
The process of converting information into a particular form or code, often for the purpose of secrecy, efficiency, or data transmission.
Decoded
Translated or interpreted from a coded or obscure form into a comprehensible or clear form.
Communication Environment
The physical and psychological context in which communication occurs, including all relevant stimuli and barriers.
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