If $\alpha, \beta\:and\:\gamma$ are the corresponding angles of the sides a, b and c respectively in an oblique triangle, then according to law of cosins, the value of the square of the side b is

Question

Accepted Answer

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

Answer

$b^{2}=b^{2}+c^{2}-2bc\cos\alpha$

Answer

$b^{2}=b^{2}+c^{2}+2bc\cos\alpha$

Answer

$b^{2}=c^{2}+a^{2}+2ac\cos\alpha$