Thus, the integrand is given by
1
(
1) (
2)
x
x
+
+
 =
1
–1
1
2
x
x
+
+
+
Therefore,
(
1) (
2)
dx
x
x
+
+
∫
 =
1
2
dx
dx
–
x
x
+
+
∫
∫
= log
1
log
2
C
x
x
+
−
+
+
=
1
log
C
2
xx
+
+
+
Remark The equation (1) above is an identity, i e a statement true for all (permissible)
values of x Some authors use the symbol ‘≡’ to indicate that the statement is an
identity and use the symbol ‘=’ to indicate that the statement is an equation, i