已知α,β∈[-π/2,π/2] α+β<0,若sinα=1/3,sinβ=1-α,求实数α取值范围

问题描述:

已知α,β∈[-π/2,π/2] α+β<0,若sinα=1/3,sinβ=1-α,求实数α取值范围

∵α,β∈[-π/2,π/2] α+β<0,若sinα=1/3∴α=arcsin1/3-π/2<β<-arcsin1/3∴sin(-π/2)<sinβ<sin(-arcsinβ1/3)即 -1<sinβ<-1/3有 -1<1-a<-1/3→-2<-a<-4/3→4/3<a<2即实数a的取值范围是(-4...