Express in the form , where and .
Answer and explanation
Correct answer: B.
- Step 1: Expand the target form: . Equating coefficients with gives and .
- Step 2: Find the amplitude: . Dividing the equations yields . Thus the expression is .
Answer
.
Why not the others: The form expands to , which has a positive sine term; uses instead of and swaps the angle; uses an incorrect amplitude calculation.
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