Solve the equation for ? if . Do not use a calculator.
? 
2cos ? + 1 = 0
? 

A. 60°; 120°
B. 45°; 315°
C. 120°; 240°
D. 60°; 300°
E. 45°; 45°

Answer: C

Mathematics

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Change the exponential expression to an equivalent expression involving a logarithm.4-2 = 

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C. log4-2 = 
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