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I need help with this practice problem It has two additional pictures of the answer options that go along, I will send you these

I need help with this practice problem It has two additional pictures of the answer-example-1
User Viona
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1 Answer

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Given the trigonometric equation:


2\cos ^2x=\cos x

We will solve the equation as follows:


\begin{gathered} 2\cos ^2x-\cos x=0 \\ \cos x(2\cos x-1)=0 \\ \cos x=0\rightarrow x=(\pi)/(2),(3\pi)/(2) \\ 2\cos x=1\rightarrow\cos x=(1)/(2)\rightarrow x=(\pi)/(3),(5\pi)/(3) \end{gathered}

So, the answer will be:


x=\mleft\lbrace(\pi)/(3),(\pi)/(2),(3\pi)/(2),(5\pi)/(3)\mright\rbrace

User Tru
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