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,
答
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