Find the exact value of cos (2x) if sec x = -2, and x is in Quadrant III. Draw a picture of a reference triangle around angle x, labeled, for full credit
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Step 1: Given that sec(x) = 2 and x is in Quadrant II, we can determine that cos(x) = -1/2 and sin(x) = √3/2 based on the triangle in Quadrant II. Show more…
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