trigonometric math

Question

Solve  for the smallest three positive solutions.Give your answers accurate to at least two decimal places, as a list separated by commas

Answer 1

3cos(3x) = 2

cos(3x) = 2/3

Cos^-1(2/3) = 0.84

3x = 0.84 + 2kπ or 5.44 + 2kπ (cosine is positive in quadrants 1 and 4)

x = 0.28 + (2/3)kπ or 1.81 + (2/3)kπ, k = 0, 1, -1, 2, -2, ...

If k = 0, then x = 0.28 or 1.81

If k = 1, then x = 2.37 or 3.90

The smallest three positive solutions (in radians)are approximately 0.28, 1.81, and 2.37