if `cos^2A=1/2` then `sin^2A`

If cos theta+cos^(2)theta=1 then sin^(2)theta+2sin^(2)theta+sin^(2)theta=

If A= 30^@ verify that :- cos2A=1- 2sin^2A .

If A=30^(@) , then prove that : 2cos^(2)A-1=1-2sin^(2)A

If A=30^(@) , then prove that : 2cos^(2)A-1=1-2sin^(2)A

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

cos^4A-sin^4A is equal to (a) 2cos^2A+1 (b) 2cos^2A-1 (c) 2sin^2A-1 (d) 2sin^2A+1

If A = 30^(@) , then Prove that : (i) sin 2A = 2 sin A cos A = (2 tan A)/(1 + tan^(2)A) (ii) 2 cos^(2)A - 1 = 1 - 2 sin^(2) A

Prove the following identity : cos^4 theta- sin^4 theta= cos^2 theta-sin^2 theta= 2 cos^2 theta-1=1-2 sin^2 theta .

prove : sin^8θ-cos^8θ = (sin^2 theta - cos^2 theta) (1- 2 sin^2 theta cos^2 theta)

Prove that : sin^8 theta- cos^8 theta= (sin^2 theta- cos^2 theta)(1-2 sin^2 theta cos^2 theta) .