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What is the value of the product of $ sin\left( \cfrac { 2\pi }{ 3 } \right) $ and $ cos\left( \cfrac { 7\pi }{ 6 } \right) $ ?

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$ -\cfrac { 3 }{ 4 } $

$ -\cfrac {1 }{ 4 } $

$ \cfrac { 1 }{ 4 } $

$ \cfrac { 3 }{ 4 } $