高数函数求导1.y=3x^2-x+52.(1-x^3)/√x3.y=xsinx+cosx4.y=xsin/(1+cosx

1.y'=3×2x-1=6x-1
2.[(1-x^3)/√x]'=[x^(1/2)]'-[x^(5/2)]'=1/2×x^(-1/2)-5/2×x^(3/2)
3.y'=x'sinx+(sinx)'x+(cosx)'=sinx+xcosx-sinx=xcosx
4.y'=[(xsinx)'(1+cosx)-(1+cosx)'×xsinx]/(1+cosx)^2={[x'sinx+(sinx)'x]×(1+cosx)+sinx×xsinx}/(1+cosx)^2=[(sinx+xcosx)×(1+cosx)+x(sinx)^2]/(1+cosx)^2=[sinx+x(cosx)^2+x(sinx)^2]/(1+cosx)^2=(sinx+x)/(1+cosx)^2