y=x^3sinx+2lnx+2/x^3y'=3x^2sinx+x^3cosx+2x^2-(2lnx+2)3x^2/x^6dy=y'dx={3x^2sinx+x^3cosx+ [2-(2lnx+2)3]/x^4}dxPS:大学不用算出最终结果解题中用到的公式1.dy=y'dx 2.(uv)'=u'v+uv'3.(u/v)'=u'v-uv'/v^2...