Mark the Correct alternative in the following:

If cos A = m cos B, then =

Mark the Correct alternative in the following:

The value of sin 50^o – sin 70^o + sin 10^o is equal to

Mark the Correct alternative in the following:

sin 47^o + sin 61^o – sin 11^o – sin 25^o is equal to

Mark the Correct alternative in the following:

If A, B, C are in A.P., then

Mark the Correct alternative in the following:

If sin (B + C – A), sin (C + A – B), sin (A + B – C) are in A.P., then cot A, cot B, cot C are in