高一数学。

显示全部楼层 · 2012-8-6 15:33:16

解：(1)f(x)＝cos(2x－π/3)＋2sin(x－π/4)sin(x＋π/4)＝1/2cos2x＋√3/2sin2x＋(sinx－cosx)(sinx＋cosx)＝1/2cos2x＋√3/2sin2x＋sin2x－cos2x＝1/2cos2x＋√3/2sin2x－cos2x＝sin(2x－π/6)∴最小正周期：T＝2π/2＝π由2x－π/6＝kπ＋π/2(k∈Z)得x＝kπ/2＋π/3(k∈Z)∴函数图象的对称轴方程为：x＝kπ＋π/3(k∈Z)(2)∵x∈[－π/12，π/2]∴2x－π/6∈[－π/3，5π/6]∵f(x)＝sin(2x－π/6)在区间[－π/1...

千问 · 2012-8-6 15:33:16

f(x)＝cos(2x－π/3)＋2sin(x－π/4)sin(x＋π/4)＝1/2cos2x＋√3/2sin2x-2sin（x－π/4)cos（x-π/4)＝1/2cos2x＋√3/2sin2x－cos2x＝sin(2x－π/6)最小正周期：T＝2π/2＝π由2x－π/6＝kπ＋π/2(k∈Z)得x＝kπ/2＋π/3(k∈Z)∴...

千问 · 2012-8-6 15:33:16

f(x)＝cos(2x－π/3)＋2sin(x－π/4)sin(x＋π/4)＝1/2cos2x＋√3/2sin2x-2sin（x－π/4)cos（x-π/4)＝1/2cos2x＋√3/2sin2x－cos2x＝sin(2x－π/6)最小正周期：T＝2π/2＝π由2x－π/6＝kπ＋π/2(k∈Z)得x＝kπ/2＋π/3(k∈Z)∴...

千问 · 2012-8-6 15:33:16