solve the equation on the interval 0 2pi 2cos3theta1Solution

solve the equation on the interval [0, 2pi]       2cos(3theta)=1

Solution

2cos(3theta)=1

cos(3theta) = 1/2 = cos(pi/3) = cos(5pi/3) = cos(7pi/3) = cos(11pi/3) = cos(13pi/3) = cos(17pi/3)

3theta = pi/3 , 5pi/3 , 7pi/3 , 11pi/3 , 13pi/3 ,17pi/3

theta = pi/9 , 5pi/9, 7pi/9, 11pi/9 , 13pi/9 , 17pi/9