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2 cos theta + sqrt3=0
2 cos theta =-sqrt3
cos theta =-sqrt3/2
210degrees = 7pi/6
150degrees = 5pi/6
My question is this: Should the answer be merely ( 7pi/6 or 5pi/6 ) OR should the answer be ( 7pi/6 + k pi, k E Z or 5pi/6 + 2k pi, k E Z ) ?
Also, if the second choice is correct; why?
Please & thank you!