高中数学必修4(人教版)第137页习题 A组1.2.
2019-06-25
高中数学必修4(人教版)第137页习题 A组1.2.
优质解答
1.(1) cos(3π/2-α)=cos(3π/2)cosα+sin(3π/2)sinα= -sinα
(2)sin(3π/2-α)=sin(3π/2)cosα-cos(3π/2)sinα=-cosα
(3)cos(π-α)=cosπcosα+sinπsinα= -cosα
(4)sin(π-α)=sinπcosα-cosπsinα= sinα
2.∵cosα=3/5 且0
1.(1) cos(3π/2-α)=cos(3π/2)cosα+sin(3π/2)sinα= -sinα
(2)sin(3π/2-α)=sin(3π/2)cosα-cos(3π/2)sinα=-cosα
(3)cos(π-α)=cosπcosα+sinπsinα= -cosα
(4)sin(π-α)=sinπcosα-cosπsinα= sinα
2.∵cosα=3/5 且0