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19 votes
19 votes
Which expression is equivalent to cos120°?

cosine 60 degrees°
cos240°
cos300°
cos420°

User Mjsabby
by
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2 Answers

22 votes
22 votes
cos120°=-5
cos240°=-5
User Leshow
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17 votes
17 votes

Answer:

The correct answer for the given question is option b) cos 240 degrees.

This means that the expression cos 120 degrees can also be written as cos 240 degrees.

This because cos 240 degrees = -1/2 = cos 120 degrees.

This happens because the second and third quadrants carry the same signs.

User John Resig
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2.9k points