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1983 AMC 12 Question 11

AMC12 · 1983 AMC 12

Question 11

Simplify $\sin(x-y)\cos y$${}+\cos(x-y)\sin y.$
  1. $1$
  2. $\sin x$
  3. $\cos x$
  4. $\sin x\cos2y$
  5. $\cos x\cos2y$