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Grade 12 · Trigonometry
Compound & Double Angle Identities (Grade 12)
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/ 26
Answer all questions. Show all your working — marks are awarded for method as well as the final answer.
- 1Expand cos(A − B).(1)
- 2Expand sin(A + B).(1)
- 3Determine the exact value of cos 75° without a calculator.(3)
- 4Determine the exact value of sin 15° without a calculator.(3)
- 5Write down the three forms of cos 2A.(3)
- 6If sin θ = 3/5 and θ is acute, determine cos 2θ.(3)
- 7If sin θ = 3/5 and θ is acute, determine sin 2θ.(3)
- 8Prove that (sin 2A)/(1 + cos 2A) = tan A, and state the restriction on A.(5)
- 9Simplify 2 sin 15° cos 15°.(2)
- 10Why is sin(A + B) ≠ sin A + sin B?(2)
TOTAL: 26 marks