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Multiple Choice
Evaluate each expression. cot(611π)
A
21
B
−33
C
−3
D
2
Verified step by step guidance
1
Step 1: Recall the definition of cotangent. The cotangent function is defined as cot(θ) = cos(θ) / sin(θ). To evaluate cot(11π/6), we need to find the cosine and sine of 11π/6.
Step 2: Determine the reference angle and quadrant. The angle 11π/6 is in the fourth quadrant, and its reference angle is π/6. In the fourth quadrant, cosine is positive, and sine is negative.
Step 3: Use the unit circle values for π/6. From the unit circle, cos(π/6) = √3/2 and sin(π/6) = 1/2. Since 11π/6 is in the fourth quadrant, cos(11π/6) = √3/2 and sin(11π/6) = -1/2.
Step 4: Substitute the values of cosine and sine into the cotangent formula. cot(11π/6) = cos(11π/6) / sin(11π/6) = (√3/2) / (-1/2).
Step 5: Simplify the expression. Dividing (√3/2) by (-1/2) is equivalent to multiplying √3/2 by -2/1, which simplifies to -√3.