已知tan2a =3求(cos²a -sin²a )÷sina cosa
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/12 21:39:51
![已知tan2a =3求(cos²a -sin²a )÷sina cosa](/uploads/image/z/2758208-32-8.jpg?t=%E5%B7%B2%E7%9F%A5tan2a+%3D3%E6%B1%82%EF%BC%88cos%26%23178%3Ba+-sin%26%23178%3Ba+%EF%BC%89%C3%B7sina+cosa)
x){}KKlmlz#9XM:QA83~v ?Q &Hv6Nb[ (Q?P(a5ҏspA`c<;\du
已知tan2a =3求(cos²a -sin²a )÷sina cosa
已知tan2a =3求(cos²a -sin²a )÷sina cosa
已知tan2a =3求(cos²a -sin²a )÷sina cosa
(cos²a -sin²a )÷sina cosa
=cos2a/[1/2sin2a]
=2/[sin2a/cos2a]
=2/tan2a
=2/3