若x∈[π/6,π/3]则函数f(x)=2cos²x+sinx-1的值域为?

问题描述:

若x∈[π/6,π/3]则函数f(x)=2cos²x+sinx-1的值域为?

0-1A-1,2B-2,0 C 1/2(根号三-1),9/8 D 1/2(根号三-1),1