第2个回答 2023-10-03
3.
(1)
y=√arccosx
y'
=(1/2)(arccosx)^(-1/2) . (arccosx)'
=(1/2)(arccosx)^(-1/2) . [-1/√(1-x^2) ]
=-1/[2.√arccosx.√(1-x^2)]
(2)
y=[cos(2-4x)]^2
y'
=2cos(2-4x).[cos(2-4x)]'
=2cos(2-4x).[-sin(2-4x)].(2-4x)'
=2cos(2-4x).[-sin(2-4x)].(-4)
=8cos(2-4x).sin(2-4x)
(3)
y=ln(lnx)
y'
=(1/lnx)(lnx)'
=(1/lnx)(1/x)
=1/[xlnx]
(4)
y=(x+2lgx)^3
y'
=3(x+2lgx)^2. (x+2lgx)'
=3(x+2lgx)^2. [1+2/(ln10x)]