(V)
Properties (III) and (IV) can be generalised to a finite number of functions
f1, f2, , fn and the real numbers, k1, k2, , kn giving
[
]
1 1
2 2
( )
( )
( )
n
n
k f x
k f
x k f
x
dx
+
+
+
∫
= 
1
1
2
2
( )
( )
( )
n
n
k
f x dx
k
f
x dx