(1)已知cos[(π/3)-a]=根号3/3,求sin[5π/6)-a]+sin^2[(2π/3)+a]的值
问题描述:
(1)已知cos[(π/3)-a]=根号3/3,求sin[5π/6)-a]+sin^2[(2π/3)+a]的值
(2)求值:log8(3)*log9(2)+log1/2(三次根号下16)-(-3又3/8)^(-2/3)+(1.5)^-2
答
(1)cos[(π/3)-a]=√3/3(5π/6-a)-(π/3-a)=π/2(5π/6-a)=(π/2)+(π/3-a)sin[(5π/6-a)=sin[(π/2)+(π/3-a)]=cos(π/3-a)=√3/3(2π/3+a)+(π/3-a)=πsin[(2π/3+a)=sin[(π/3-a)]=±√3/3sin^2[(2π/3+a)=sin[(...