cos300度= tan4分之7派=
问题描述:
cos300度= tan4分之7派=
答
300°=360°-60°
cos300°=cos(360°-60°)
诱导公式
=cos(-60°)
=cos60°
=1/2
tan7π/4
=tan(2π-π/4)
=tan(-π/4)
=-tanπ/4
=-1