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If sin 3y = cos 2y and 0o \(\leq\) 90o, find the value of y

If sin 3y = cos 2y and 0o \(\leq\) 90o, find the value of y
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  • A 18o
  • B 36o
  • C 54o
  • D 90o
Correct Answer: Option A
Explanation:
sin 3y = cos 2y, but sin \(\theta\) = cos(90 - \(\theta\))
sin 3y = cos(90 - 3y)
cos(90 - 3y) = cos 2y
90 - 3y = 2y
5y = 90
y = \(\frac{90}{5}\)
y = 18o

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