" (ii) "cos3B=4cos^(3)B-3cos B

Derivative of cos^(-1)(4cos^(3)x-3cos x) is (A) 1 (B) 2 (C) 3 (D) 4

Show that in any Delta ABC, a ^(3) cos 3B+3a^(2)b cos (2B-A)+3ab^(2) cos (B-2A) +b^(3) cos 3A =c^(3)

ig sin B=(1)/(2) then prove that 3cos B-4cos^(3)B=0

In a triangle ABC if sin B=(1)/(2)=cos A then 3cos B-4cos^(3)B=(i)sin C(ii)cos C(iii)0(iv)3(sqrt(3))/(2)

Prove that a^(3) cos (B-C) + b^(3) cos (C - A) + c^(3) cos (A-B) = 3abc .

sqrt(2)cos A=cos B+cos^(3)B, and sqrt(2)sin A=sin B-sin^(3)B then sin(A-B)+-1(b)+-(1)/(2)(c)+-(1)/(3)(d)+-(1)/(4)

If cos A+coa B+cos C=sin A+sin B+sin C=0 the values of (cos3A+cos3B+cos C)/(cos(A+B+C))

If A+B+C=180^(@) " then " cos 3A + cos 3B+ cos 3C=