$\"\"$

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The expression is $\"Syntax$ .

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Trigonometric inverse property: $\"begin$ .

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Let $\"Syntax$ .

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$\"italic$ .

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$\"\"$

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Pythagorean theorem $\"\"$ .

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So, rationalize with 1/5.

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$\"\"$

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$\"\"$

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$\"italic$ $\"\"$

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$\"Syntax$ .

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Substitute $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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The exact value of $\"Syntax$ is $\"\"$ .