问题描述: 求下列函数的导数:(1)y=5x^2-4x+1 (2)y=(2x^2-1)(3x^2+1) (3)y=(x+cosx)/(x+sinx) 1个回答 分类:数学 2014-10-23 问题解答: 我来补答 1. y' = 10x - 42. y' = 4x(3x^2 - 1) + 6x(2x^2 - 1) = 24x^2 - 10x 3. y' = [(1-sinx)(x+sinx) - (1+cosx)(x+cosx)]/(x+sinx)^2 = (sinx - xsinx - cosx - xcosx - 1)/(x+sinx)^2 展开全文阅读