Θ∈(π/2,3π/4) sin2Θ∈a sinΘ+cosΘ

问题描述:

Θ∈(π/2,3π/4) sin2Θ∈a sinΘ+cosΘ

∵ Θ∈(π/2,3π/2)
∴sinΘ=a0 cosΘ|cosΘ|
∵(sinΘ+cosΘ)^2=1+sin2Θ=a+1
∴sinΘ+cosΘ=∫(a+1)