微积分题打勾的题在线等,急~
1个回答

y=ln(-6x^2+7x+3)此题需用运用复合函数的求导法则,则有:

y'=[1/(-6x^2+7x+3)]*(-6x^2+7x+3)'

=[1/(-6x^2+7x+3)]*(-12x+7)

=(7-12x)/(-6x^2+7x+3).

y=sin^2x+cos^4x此题和函数和复合函数的综合求导,步骤为:

y'=2sinx*(sinx)'+4cos^3x*(cosx)'=2sinxcosx+4cos^3x(-sinx)

=2sinxcosx(1-2cos^2x)

=-sin2x*cos2x

=-(1/2)sin4x

y=1/(x-x^2)此题是函数商的求导,步骤为:

y'=-(x-x^2)'/(x-x^2)^2

=-(1-2x)/(x-x^2)^2.