Answer: [0, 10].
- A [−5, 5]
- B [0, 10]
- C [1, 9]
- D [2, 8]
Correct answer: B. [0, 10]
Explanation: 3sinx + 4cosx lies in [−5, 5] since the amplitude is √(9+16) = 5. Adding 5 gives [0, 10].
Unit circle with standard angles 0, 30, 45, 60, 90 degrees; at 45 degrees the point is (cos45, sin45) = (1/sqrt2, 1/sqrt2).
Concept context
Ratios, identities, and applications in triangles