" ख) सिद्ध कीजिए "CosA" ."cos(60+A).cos(60-A)=1/4Cos3A

Prove that : cos Acos(60-A)cos(60+A)=1/4cos3A

Prove that :cos A cos(60-A)cos(60+A)=(1)/(4)cos3A

Prove that: cos Acos(60^0-A)cos(60^0+A)=1/4cos3A

Prove that: (i) cos A cos(60^(@)-A)cos (60^(@)+A)=(1)/(4)cos 3A (ii) "tan" A+"tan"(60^(@)+A)-"tan"(60^(@)-A)=3 tan 3A .

(ii) Prove cos x cos(60-x)cos(60+x)=(1)/(4)cos3x

Prove that: cosA. Cos(60^(@)+A)cos(60^(2)-A)=1/4 cos3A

Prove that: cos A cos(60^(@)-A)cos(60^(@)+A)=(1)/(4)cos3A

If A=30^(@) , show that : 4cosAcos(60^(@)-A)*cos(60^(@)+A)=cos3A

(sec60)(cos60) =……………

Select and write the correct answer from the given alternatives in each of the following: cosA.cos(60^@-A).cos(60^@+A) =