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Solve Sec 5theta/4=2

User Orsy
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1 Answer

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\sec(5\theta)/(4)=2\\ (1)/(\cos (5\theta)/(4))=2\\ \cos (5\theta)/(4)=(1)/(2)\\ (5\theta)/(4)=(\pi)/(3)+2k\pi \vee (5\theta)/(4)=-(\pi)/(3)+2k\pi\\ 5\theta=(4\pi)/(3)+8k\pi \vee 5\theta=-(4\pi)/(3)+8k\pi\\ \boxed{\theta=(4\pi)/(15)+(8k\pi)/(5) \vee \theta=-(4\pi)/(15)+(8k\pi)/(5)}
User Haytch
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