The solutions are theta = 0 degrees or theta = 180 degrees.
There are NO other solutions in the interval 0 <= theta < 360 degs.
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Yes, I really missed that roots. Sorry.
Answer by greenestamps(13203) (Show Source): You can put this solution on YOUR website! Tutor ikleyn's answers are usually reliable; but she missed something here. Since she didn't show any work in her response to your question, I don't know how she arrived at her incorrect answer.
or
gives and , as shown in ikleyn's response.
gives the two additional solutions and
Graphing the two expressions with a graphing calculator confirms the four solutions.