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Find the exact value of cos open parentheses fraction numerator 7 straight pi over denominator 6 end fraction close parentheses by using the unit circle.

Find the exact value of cos open parentheses fraction numerator 7 straight pi over-example-1
User KolKir
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Answer:

The exact value of cos(7π/6) can be found using the unit circle. 7π/6 is equivalent to 210 degrees, which places the angle in the third quadrant of the unit circle. The reference angle for 7π/6 is π/6 or 30 degrees. The cosine of an angle in the third quadrant is negative, so cos(7π/6) = -cos(π/6). Since cos(π/6) = √3/2, we have cos(7π/6) = -√3/2.

Explanation:

User Vijeesh
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