3cos(6x)=2 for the three smallest positive solutions

Question

Give your answers accurate to at least two decimal places, as a list separated by commas.

Answer 1

cos(6x) = 2/3; 6x = cos^-1(2/3) + 2πn; or 6x = 2π(n + 1) - cos^-1(2/3);

x = 0.14 + πn/3 or x = - 0.14 + π(n + 1)/3