Mark the Correct alternative in the following:

In any ∆ABC, a (b cos C – c cos B) =

Mark the Correct alternative in the following:

In any ∆ABC, (bc cos A + ca cos B + ab cos C) =

Mark the Correct alternative in the following:

In a triangle ABC, a = 4, b = 3, ∠A = 60^o then c is a roof of the equation

Mark the Correct alternative in the following:

In a ∆ABC, if (c + a + b) (a + b – c) = ab, then the measure of angle C is

Mark the Correct alternative in the following:

In any ∆ABC, the value of 2ac is