How do you simplify sin4θ−cot2θ to trigonometric functions of a unit θ? Trigonometry Trigonometric Identities and Equations Double Angle Identities 1 Answer Shwetank Mauria Jun 23, 2016 sin4θ−cot2θ = 4sinθcos3θ−4sin3θcosθ−12(cotθ−tanθ) Explanation: we use sin2A=2sinAcosA and cos2A=cos2A−sin2A Hence sin4θ−cot2θ=2sin2θcos2θ−cos2θsin2θ = 4sinθcosθ(cos2θ−sin2θ)−cos2θ−sin2θ2sinθcosθ = 4sinθcos3θ−4sin3θcosθ−cosθ2sinθ+sinθ2cosθ = 4sinθcos3θ−4sin3θcosθ−12(cotθ−tanθ) 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 sin2x=cosx for the interval [0,2π]? How do you find all solutions for 4sinθcosθ=√3 for the interval [0,2π]? How do you simplify cosx(2sinx+cosx)−sin2x? If tanx=0.3, then how do you find tan 2x? If sinx=53, what is the sin 2x equal to? How do you prove cos2A=2cos2A−1? See all questions in Double Angle Identities Impact of this question 1514 views around the world You can reuse this answer Creative Commons License