" 20."sin^(3)A-cos^(6)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)

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

sin^(6)A + cos^(6)A + 3sin^(2)A.cos^(2)A=

sin ^ (8) A-cos ^ (8) A = (sin ^ (2) A-cos ^ (2) A) (1-2sin ^ (2) A cos ^ (2) A)

sin^(6)A+cos^(6)A+3sin^(2)A cos^(2)A=0 b.1c2d.3

(sin^(2)3A)/(sin^(2)A)-(cos^(2) 3A)/(cos^(2)A)=

(sin^(2)3A)/(sin^(2)A)-(cos^(2)3A)/(cos^(2)A)=

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

Prove that: (sin A + cos A)/(sin A - cos A) + (sin A - cos A)/(sin A + cos A) = (2)/(sin^(2)A-cos^(2)A)=(2)/(2sin^(2)A-1)=(2)/(1-2 cos^(2)A) .

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)