令y=sinu u=0.5x+π/3 u在[2kπ-π/2,2kπ+π/2],y为增区间,两增区间在相对应的区间相复合为增函数,即2kπ-π/2<=0.5x+π/3<=2kπ+π/2,即k=0,x为[-5/3π,π/3]为增区间 同理2kπ+π/2<=0.5x+π/3<=2kπ+3π/2 即k=0,x为[π/3,2π]为减区间,k=-1,x为,,x为[-2π,-5π/3)]为减区间
递增区间: -π/2<1/2x+π/3<π/2 解得:(-5π/3)递减:2kπ+π/2<1/2x+π/3<3π/2+2kπ,又因为X属于[-2π,2π】。解得:-2π(π/3)