已知sin(π-θ)-cos(π+θ)=√2/3,其中π/2<θ<π,求下列各式的值:(1)sinθ-cosθ;(2)sin³(π/2-θ)+cos³(π/2+θ)

问题描述:

已知sin(π-θ)-cos(π+θ)=√2/3,其中π/2<θ<π,求下列各式的值:
(1)sinθ-cosθ;
(2)sin³(π/2-θ)+cos³(π/2+θ)

已知sin(π-θ)-cos(π+θ)=√2/3,其中π/2<θ<π,求下列各式的值:(1)sinθ-cosθ;(2)sin³(π/2-θ)+cos³(π/2+θ) (1)sin(π-θ)-cos(π+θ)=√2/3sinθ+cosθ=√2/3(sinθ+cosθ)²=2/9...