设y=x乘以根号x+lncosx,求dy,

问题描述:

设y=x乘以根号x+lncosx,求dy,

y=x乘以根号x+lncosx
=x^(3/2)+lncosx
y'=3/2 √x +1/cosx· (-sinx)
=3√x /2 -tanx
dy=(3√x /2 -tanx)dx