Find the Value Using the Unit Circle sin(120)

Problem

sin(120)

Solution

1. Identify the angle 120 on the unit circle. This angle is located in the second quadrant.

2. Determine the reference angle by subtracting 120 from 180

180−120=60

3. Recall the sine value for the reference angle 60

sin(60)=√(,3)/2

4. Determine the sign of the sine function in the second quadrant. Since the ycoordinate is positive in the second quadrant, the sine value remains positive.

sin(120)=sin(60)

Final Answer

sin(120)=√(,3)/2

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