Question 19 • Mathematics III
Since cosecant θ = −5/2, sine θ = −2/5. In quadrant III, both x and y are negative, and sine equals y/r, where r = √(x² + y²). Choice B has x = −√21 and y = −2, giving r = √(21 + 4) = 5 and y/r = −2/5, so the coordinates are (−√21, −2).
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