If sinθ+cosθ=p, what is sin2θ+cos4θ in terms of p ? Trigonometry Right Triangles Relating Trigonometric Functions 1 Answer Cesareo R. Feb 22, 2017 1−(p2−12)2 Explanation: (sinθ+cosθ)2=1+2sinθcosθ=p2 so sinθcosθ=p2−12 now sin2θ+cos4θ=sin2θ+(1−sin2θ)cos2θ=1−sin2θcos2θ and putting all together sin2θ+cos4θ=1−(p2−12)2 Answer link Related questions What does it mean to find the sign of a trigonometric function and how do you find it? What are the reciprocal identities of trigonometric functions? What are the quotient identities for a trigonometric functions? What are the cofunction identities and reflection properties for trigonometric functions? What is the pythagorean identity? If secθ=4, how do you use the reciprocal identity to find cosθ? How do you find the domain and range of sine, cosine, and tangent? What quadrant does cot325∘ lie in and what is the sign? How do you use use quotient identities to explain why the tangent and cotangent function have... How do you show that 1+tan2θ=sec2θ? See all questions in Relating Trigonometric Functions Impact of this question 7769 views around the world You can reuse this answer Creative Commons License