F(x)=√(1+sinx)+√(1-cosx)
F’(x)=cosx/[2√(1+sinx)]+sinx/[2√(1-cosx)]=0
cosx√(1-cosx)=-sinx√(1+sinx)
cosx=-sinx==>x1=2kπ+3π/4,x2=2kπ+7π/4
可以证明函数F(x)在x1,x2点取极大值,(证明过程复杂略)
F(3π/4)=2√(1+√2/2)
F(7π/4)=√(1-√2/2)+√(1+√2/2)
F(0)=F(3π/2)=1,函数F(x)在点2kπ,x2=2kπ+3π/2不连续
∴函数F(x)的取值范围,即值域为[1,2√(1+√2/2)]