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16 votes
16 votes
Can someone help me???

Which of the following is equal to 1/2 or -1/2? Check all that apply.

Sin (7π/6)

Sin (4π/3)

Cos (5π/3)

Cos (π/6)

Cos (5π/6)

Sin (5π/6)

User Gotye
by
2.8k points

2 Answers

4 votes
4 votes

Answer:

Below in bold.

Explanation:

The sine is positive in the first and second quadrants and negative in other 2.

The cosine is positive in the first and 4th quadrants and negative in other 2.

Note that sin(pi/6) = 1/2 and cos(pi/3 = 1/2).

sin(7pi/6) = 1/2

cos(5pi/3) = 1/2

sin(5pi/6) = 1/2

User Starpause
by
3.1k points
14 votes
14 votes

Answer:

Cos (5π/3)

Cos (π/6)I think this one

User Mdhughes
by
3.1k points