高一数学三角函数化简求值,

(√3*tan12-3)/[sin12(4cos^2 12-2)]
=[√3(tan12-√3)]/[2sin12(2cos^2 12-1)]
=[√3(tan12-√3)]/[2sin12(cos24)]
分子,分母同时乘以2cos12
=[2√3(sin12-√3*cos12)]/[4sin12cos12cos24]
=[2√3*(2sin(12-60))]/[2sin24cos24]
=[4√3*(-sin48)]/[sin48]
=-4√3