1.y= - 1/2sinx+b的值域为[- 1/2+b,1/2+b],得b=1/4,最大值就为1/2+1/4=3/4.
2.y=sinx-cosx-1=根号2×sin（x-π/4）-1,故最小值为根号2-1
3.由sinx在[-π/2+2kπ,π/2+2kπ]递增,令-π/2+2kπ≦2x-π/6≦π/2+2kπ可解的答案.
4.f(x)=sin(2x+π/4)-根号3cos(2x+π/4)=2sin(2x-π/12）.Max=2,T=π.
1.y= - 1/2sinx+b的值域为[- 1/2+b,1/2+b],得b=1/4,最大值就为1/2+1/4=3/4.
2.y=sinx-cosx-1=根号2×sin（x-π/4）-1,故最小值为根号2-1
3.由sinx在[-π/2+2kπ,π/2+2kπ]递增,令-π/2+2kπ≦2x-π/6≦π/2+2kπ可解的答案.
4.f(x)=sin(2x+π/4)-根号3cos(2x+π/4)=2sin(2x-π/12）.Max=2,T=π.