cos﹙∏/6-α﹚=m,﹙|m|≤1﹚,则sin﹙2∏/3-α﹚的值等于?
问题描述:
cos﹙∏/6-α﹚=m,﹙|m|≤1﹚,则sin﹙2∏/3-α﹚的值等于?
答
sin(2π/3-α)=sin[π/2+(π/6-α)]=cos(π/6-α)=cos(α-π/6)=cos(π/6-α)=m
cos﹙∏/6-α﹚=m,﹙|m|≤1﹚,则sin﹙2∏/3-α﹚的值等于?
sin(2π/3-α)=sin[π/2+(π/6-α)]=cos(π/6-α)=cos(α-π/6)=cos(π/6-α)=m