Find the Exact Value cos(89)

Problem

cos(89)

Solution

1. Identify the expression as the cosine of 89 degrees.

2. Recognize that 89 is not a standard reference angle (like 30 45 or 60 for which a simple radical form is commonly memorized.

3. Determine if the value can be simplified using sum or difference identities. While 89=45+44 or 89=60+29 these do not involve standard angles that result in a simpler exact radical form.

4. Conclude that the exact value is represented by the expression itself, as it cannot be simplified further into basic radicals without using complex trigonometric constants.

Final Answer

cos(89)=cos(89)

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