If $\alpha, \beta\:and\:\gamma$ are the measures of the angles of a triangle, and a, b and c are the lengths of sides opposite these angles then according be law of cosine, the value of $cosine\gamma$ is defined as:

Question

Accepted Answer

$\cos\gamma=\frac{a^{2}+c^{2}-b^{2}}{2ac}$

Answer

$\cos\gamma=\frac{a^{2}+c^{2}+2ab\cos\gamma}{b^{2}}$

Answer

$\cos\gamma=\frac{b^{2}+c^{2}-a^{2}}{2bc}$