f(t) = ln t^3 f'(t)= .... ln=logaritma natural

aturan rantai :

misal,
a = t^3
da/dt = 3t^2

y = ln a
dy/da = 1/a

dy/dt = dy/da * da/dt
= (1/a)*(3t^2)
= (3t^2)/a
= (3t^2)/(t^3)
= 3/t