(sinx-1)tanx怎么化简成[(sinx-sinπ/2)/sin(x+π/2)]sinx,x趋于π/2
问题描述:
(sinx-1)tanx怎么化简成[(sinx-sinπ/2)/sin(x+π/2)]sinx,x趋于π/2
答
(sinx-1)tanx=(sinx-sinπ/2)tanx=(sinx-sinπ/2)(sinx/cosx)
注意sin(x-π/2)=cosx