sin4x-π/3转化成cos是什么
∵ sin(-π/3) = cos[ π/2 - (-π/3) ] = cos(5π/6) = cos( π - π/6) = -cos(π/6);
转化成 cos 函数后,周期不变;
∴ sin( 4x - π/3) = cos( 4x + 5π/6)
或 sin( 4x - π/3) = -cos( 4x + π/6) 。
诱导公式:sina=cos(π/2-a)
sin(4x-π/3)
=cos[π/2-(4x-π/3)]
=cos(5π/6-4x)
热门标签: