308 STEP 4. Review the Knowledge You Need to Score High
∫
2
x^2 − 4 x
dx=
− 1
2
∫
dx
x
+
1
2
∫
dx
x− 4
=
− 1
2
ln|x|+
1
2
ln
∣∣
x− 4
∣∣
+C
=
1
2
ln
∣∣
∣∣x−^4
x
∣∣
∣∣+C.
33.
∫∞
e
dx
x
=klim→∞
∫k
e
dx
x
=klim→∞ln|x|
∣∣k
e
=klim→∞[ln|k|− 1 ]=∞