Use the product-to-sum or sum-to-product identities to find an identity for the given expression.cos 11? + cos 15?
A. 2 cos 
? cos 1?
B. cos 13? sin 2?
C. 2 cos 13? cos 2?
D. -2 sin 13? cos 2?
Answer: C
Mathematics
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Estimate the percentage.10% of 81,700
Fill in the blank(s) with the appropriate word(s).
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Solve the equation.
- 6 = 0
A. {3} B. {33} C. {39} D. ?
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Factor completely.x4 - 169
A. (x2 - 13)2 B. (x - 13)(x + 13) C. (x2 - 13)(x2 + 13) D. (x2 + 13)2
Mathematics
Simplify. Assume that variables can represent any real number.
A. z - 3 B. ?z? - 3 C. ?z - 3? D. -z + 3
Mathematics