\"\"

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The trigonometric equation is \"\" and the interval is \"\". \ \

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Consider \"\".

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Apply sum formula : \"\".

\

\"\"

\

\"\"

\

\"\"

\

\"\"

\

\"\"

\

\"\"

\

Thus, the solutions are \"\" and \"\" in the interval \"\".

\

\"\"

\

The solutions are \"\" and \"\" in the interval \"\".