Question

If cos (θ + 31°) = sin 47°, then what is the value of sin 5θ?

• A. ½
• B. 1/√2
• C. √3/2
• D. 0

Answer 1

Answer:

C. √3/2

cos (θ + 31°) = sin 47° cos (θ + 31°) = sin (90 - 43)° cos (θ + 31°) = cos 43° θ = 12° Sin 5θ = sin 60° = √3/2