How do you find the solution to #2costheta-1=0# if #0<=theta<360#?

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Answer 1 · 2017-04-27T20:33:50

#S={60^@,300^@}#

#2 cos theta-1=0#

#2cos theta = 1#

#cos theta = 1/2#

#theta = cos^-1 (1/2)#

#theta=+- 60^@ + 360^@ n#, where n are integers

#n=0, theta = 60^@, -60^@#

#n=1, theta = 420^@, 300^@#

#S={60^@,300^@}#