Question

Which one is correct

a. cos A = (b^2+ c^2+ a^2)/2bc

b. cos B = (a^2+ c^2+ b^2)/2ac

c. cos C = (a^2+ b^2+ c^2)/2ab

d. none of these

only answer needed...
no need of explanation​

Answer 1

Which one is correct

b. cos B = (a^2+ c^2+ b^2)/2ac