If sinx = 3/5 and x is in Quadrant II, what is the value of cosx?
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Correct answer: C
Explanation
Given:
sinx = 3/5
x lies in Quadrant II
According to the formula:
sin²x + cos²x = 1
(3/5)² + cos²x = 1
9/25 + cos²x = 1
cos²x = 1 − 9/25
= 16/25
cosx = √(16/25)
= 4/5
cos is negative in Quadrant II
cosx = −4/5