已知cos(π/6-α)=m(|m|≤1),求cos(5π/6+α),sin(2π/3-α)的值_数学解答

已知cos(π/6-α)=m(|m|≤1),求cos(5π/6+α),sin(2π/3-α)的值

人气：147 ℃　时间：2020-06-03 07:49:27

解答

∵cos(π/6-α)=m(|m|≤1),
∴cos(5π/6+α)
=cos[π-(π/6-α)]
=-cos(π/6-α)
=-m
sin(2π/3-α)
=sin[π/2+(π/6-α)]
=cos(π/6-α)
=m