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Given the formula for the Law of Cosines, which one of the following is an equivalent equation?

$${a}^{2}={b}^{2}+{c}^{2}-2\text{bc}\cdot\text{cos}\text{ A }$$

$\text{cos A}=\cfrac{{b}^{2}+{c}^{2}+{a}^{2}}{2\text{bc}}$

$\text{cos A}=\cfrac{{b}^{2}+{c}^{2}-{a}^{2}}{2\text{bc}}$

$\text{cos A}=\cfrac{{a}^{2}-{b}^{2}-{c}^{2}}{2\text{bc}}$

$\text{cos A}=\cfrac{{b}^{2}+{c}^{2}-{a}^{2}}{2a}$

$\text{None of the Above}$