若(sinθ)^6+(cosθ)^6=13/16,则sin2θ=_数学解答

若(sinθ)^6+(cosθ)^6=13/16,则sin2θ=

人气：285 ℃　时间：2020-08-25 10:44:25

解答

(sinθ)^6+(cosθ)^6=13/16[(sinθ)^2+(cosθ)^2][(sinθ)^4-(sinθ)^2(cosθ)^2+(cosθ)^4]=13/16(sinθ)^4-(sinθ)^2(cosθ)^2+(cosθ)^4=13/16[(sinθ)^2+(cosθ)^2]^2-3(sinθ)^2(cosθ)^2=13/161-3(sinθcosθ)...