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33 votes
33 votes
Solve -12cos x + 6 = 0 on the interval [0, 2n).OT 5T3' 3T 273' 32427 4T3,T 1176' 6

User Zev
by
2.9k points

1 Answer

19 votes
19 votes

Answer:

n/3, 5n/3

Step-by-step explanation:

Given the equation:


-12\cos x+6=0,\lbrack0,2\pi)

Subtract 6 from both sides:


\begin{gathered} -12\cos x+6-6=0-6 \\ -12\cos x=-6 \end{gathered}

Next, divide both sides by -12:


\begin{gathered} (-12\cos x)/(-12)=-(6)/(-12) \\ \cos x=0.5 \end{gathered}

Finally, solve for x in the interval [0, 2n).


\begin{gathered} x=\arccos (0.5) \\ x=(\pi)/(3) \\ x=2\pi-(\pi)/(3)=(5\pi)/(3) \end{gathered}

The first choice is correct.

User IMujagic
by
2.9k points
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