(x+π/6)+(5π/6-x)=π,(x+π/6)+(π/3-x)=π/2 根据诱导公式： sin(5π/6-x)=sin[π-(x+π/6)]=sin(x+π/6)=1/4 sin^2(π/3-x)=sin^2[π/2-(x+π/6)]=cos^2(x+π/6)=1-sin^2(x+π/6)=1-1/16=15/16 所以sin(5π/6-x)+sin^2(π/3-x)=1/4+15/16=19/16
