`[cos((A)/(2))-sin((A)/(2))]^(2)=1-sin A`

cos A=cos^(2)((A)/(2))-sin^(2)((A)/(2))=1-2sin^(2)((A)/(2))=2cos^(2)((A)/(2))-1

If A=340^(@), prove that 2sin((A)/(2))=-sqrt(1+sin A)+sqrt(1-sin A) and 2cos((A)/(2))=-sqrt(1+sin A)-sqrt(1-sin A)

cos A + cos B + cos C = 1 + 4sin ((A) / (2)) sin ((B) / (2)) sin ((C) / (2))

sin A+2sin2A+sin3A is equal to which of the following? (1.) 4sin2A cos^(2)((A)/(2))(2.)2sin2A((sin A)/(2)+(cos A)/(2))^(2)(3.)8sin A cos A cos^(2)((A)/(2))

If (cos^(4)A)/(cos^(2)B)+(sin^(4)A)/(sin^(2)B)=1 then prove that (i)sin^(2)A+sin^(2)B=2sin^(2)A sin^(2)B(ii)(cos^(4)B)/(cos^(2)A)+(sin^(4)B)/(sin^(2)A)=1

If : A+B+C= pi "then" : 1 - sin^(2)""(A)/(2) - sin^(2)""(B)/(2)+ sin^(2)""(C)/(2)= A) 2cos""(A)/(2) * cos sin ^(2)""(B)/(2) + sin^(2)""(C)/(2) B) 2 cos ""(B)/(2)* cos ""(B)/(2) * sin""(C)/(2) C) 2 cos ""(C)/(2)* cos ""(A)/(2) * sin""(B)/(2) D) 2 cos ""(A)/(2)* cos ""(B)/(2) * sin""(C)/(2)

Prove the following identities: (sin^(2)A)/(cos^(2)A)+(cos^(2)A)/(sin^(2)A)=(1)/(sin^(2)A cos^(2)A)-2

Prove the following identities: (sin+cos A)/(sin A-cos A)+(sin-cos A)/(sin A+cos A)=(2)/(sin^(2)A-cos^(2)A)=(2)/(2sin^(2)A-1)=(2)/(1-2cos^(2)A)

Show that: sin^(8)A-cos^(8)A=(sin^(2)A-cos^(2)A)(1-2sin^(2)A cos^(2)A)

Show that: sin^(8)A-cos^(8)A=(sin^(2)A-cos^(2)A)(1-2sin^(2)A*cos^(2)A)