\"\"

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The trignometry expression is \"\".

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Let \"\"

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\"\", \"\".

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Where \"\" lies in second quadrant.

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Find  \"\":

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\"\"

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\"\"

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\"\".

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\"\"

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\"\".

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Apply the inverse trigonometric identity: \"\", where \"\".

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\"\"

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The exact value of  \"\".

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\"\"

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\"\".