$\"\"$

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Need to prove $\"\"$ , if $\"\"$ .

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Let $\"\"$ .

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$\"\"$ .

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$\"\"$

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$\"\"$

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Apply reciprocal identity: $\"\"$ .

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$\"\"$

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Apply co-function identities: $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Substitute $\"\"$ .

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$\"\"$ .

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$\"\"$

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$\"\"$ .