若(sinθ)^6+(cosθ)^6=13/16,则sin2θ=

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若(sinθ)^6+(cosθ)^6=13/16,则sin2θ=

若(sinθ)^6+(cosθ)^6=13/16,则sin2θ=
若(sinθ)^6+(cosθ)^6=13/16,则sin2θ=

若(sinθ)^6+(cosθ)^6=13/16,则sin2θ=
(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=13/16
1-3(sinθcosθ)^2=13/16
3(sinθcosθ)^2=3/16
(sinθcosθ)^2=1/16
sin2θ^2=1/4
sin2θ=±1/2