Question #78bc0 Trigonometry Trigonometric Identities and Equations Double Angle Identities 1 Answer P dilip_k Mar 1, 2017 6sin^4x6sin4x =6/4xx(2sin^2x)^2=64×(2sin2x)2 =3/2xx(1-cos2x)^2=32×(1−cos2x)2 =3/2xx(1-2cos2x+cos^2 2x)=32×(1−2cos2x+cos22x) =3/2xx(1-2cos2x+1/2(1+cos4x))=32×(1−2cos2x+12(1+cos4x)) =3/4xx(3-4cos2x+cos4x))=34×(3−4cos2x+cos4x)) Answer link Related questions What are Double Angle Identities? How do you use a double angle identity to find the exact value of each expression? How do you use a double-angle identity to find the exact value of sin 120°? How do you use double angle identities to solve equations? How do you find all solutions for sin 2x = cos xsin2x=cosx for the interval [0,2pi][0,2π]? How do you find all solutions for 4sinthetacostheta=sqrt(3)4sinθcosθ=√3 for the interval [0,2pi][0,2π]? How do you simplify cosx(2sinx + cosx)-sin^2xcosx(2sinx+cosx)−sin2x? If tan x = 0.3tanx=0.3, then how do you find tan 2x? If sin x= 5/3sinx=53, what is the sin 2x equal to? How do you prove cos2A = 2cos^2 A - 1cos2A=2cos2A−1? See all questions in Double Angle Identities Impact of this question 1849 views around the world You can reuse this answer Creative Commons License