Answer:
The correct answer is marked.
Explanation:
You are given the cosine of an angle, and asked to find the corresponding sine. The relation is ...
sin(x)² = 1 - cos(x)²
sin(x)² = 1 - (-4/√305)² = 1 - 16/305 = 289/305
sin(x) = √(289/305) = 17/√305
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The arccos function will return an angle in the first or second quadrant. This negative cosine corresponds to a 2nd-quadrant angle. The sine is positive in the second quadrant.