\"\"

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c)  \"italic

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The difference formula for the sine function: \"italic.

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Substitute \"italic

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The value are available in problem no 33a.

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\"equal

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\"equal                (Simplify)

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\"equal                   (Rewrite the expression with common denominator)

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\"equal                     (Take out common term \"begin)

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\"equal                             (Simplify)

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\"equal                               (Simplify)\"\"

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The value of \"italic\"equal.