$\"\"$

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The trigonometric equation is $\"\"$ on $\"\"$ .

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$\"\"$

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$\"\"$

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Solve $\"\"$ on a calculator, first set the mode to radians.

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Inverse cosine function definition: $\"\"$ .

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$\"\"$

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$\"\"$ .

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Round to two decimal values.

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$\"\"$ .

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The solution $\"\"$ is lies on the interval $\"\"$ .

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$\"\"$

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The general solution of $\"\"$ is $\"\"$ , where $\"\"$ is an integer.

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$\"\"$ .

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Substitute $\"\"$ in the above expression. $\"\"$ and $\"\"$

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$\"\"$ and $\"\"$ .

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$\"\"$ is not lies on the interval $\"\"$ .

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The solution set for $\"\"$ on $\"\"$ are $\"\"$ .

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$\"\"$

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$\"\"$ .