Solve : `5cos2theta+2cos^2(theta/2)+1=0,-pi lt theta lt pi` – InterviewSolution

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1.	Solve : `5cos2theta+2cos^2(theta/2)+1=0,-pi lt theta lt pi`
Answer» `5cos2theta+2cos^2(theta/2)+1=0` `5(2cos^2theta-1)+(1+costheta+1=0` `10cos^2theta-5+1+costheta+1=0` `10cos^2theta+costheta-3=0` `10cos^2theta+6costheta-5costheta-3=0`

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