tanβ=-3,(5sin^3 β+cos β)/(2cos^3 β+sin^2 βcos β)

问题描述:

tanβ=-3,(5sin^3 β+cos β)/(2cos^3 β+sin^2 βcos β)
求其值

(5sin³β+cos β)/(2cos³β+sin²βcosβ)=[sinβ(5sin²β+cosβ/sinβ)]/[cosβ(2cos²β+sin²β)]=tanβ[5sin²β+1/tanβ]/[2(1-sin²β)+sin²β]=tanβ[5sin²β+...