B. Add 3 and divide by 6 to isolate cos(x) and then it reduces to 1/2.
C. You start thinking of what angle would make cosine equal 1/2.
D1. You have to remember your 30-60-90 triangles and unit circle and find out that x = π/3.
D2. You also have to think of the other values between 0 and 2π. Angles equal to π/3 would be 2π/3, 4π/3, and 5π/3, but at 2π/3 and 4π/3, cosine is negative.
Answers & Comments
Verified answer
A. 6 cos(x) − 3 = 0
B. cos(x) = 1/2
C. x = arccos (1/2)
D. x = π/3, 5π/3
Explanation.
A. Start
B. Add 3 and divide by 6 to isolate cos(x) and then it reduces to 1/2.
C. You start thinking of what angle would make cosine equal 1/2.
D1. You have to remember your 30-60-90 triangles and unit circle and find out that x = π/3.
D2. You also have to think of the other values between 0 and 2π. Angles equal to π/3 would be 2π/3, 4π/3, and 5π/3, but at 2π/3 and 4π/3, cosine is negative.