We
take log x as the first function and the constant function 1 as the second function Then,
the integral of the second function is x Hence,
(log 1)
x
dx
∫
 = log
1
[
(log ) 1
]
d
x
dx
x
dx dx
dx
−
∫
∫
∫
=
1
(log )
–
log
C
x
x
x dx
x
x – x
x
⋅
=
+
∫