已知函数f(x)=cos²x/2-sin²x/2+sin+求f(x)最小正周期

问题描述:

已知函数f(x)=cos²x/2-sin²x/2+sin+求f(x)最小正周期
当x0∈(0,π/4)且f(x0)=4根号2分之5时,求f(x0+π/6)的值

f(x)=cos²x/2-sin²x/2 + sinx=cosx + sinx=根号2(sinxcosπ/4+cosxsinπ/4)=根号2 sin(x+π/4)最小正周期2π x0∈(0,π/4)且f(x0)=4根号2分之5,即:根号2 sin(x0+π/4)=5/(4根号2)sin(x0+π/4)=5/8...