CPM Homework Help : CALC Problem 11-69

Examine the integrals below. Consider the multiple tools available for integrating and use the best strategy. After evaluating each integral, write a short description of your method.

$\int \frac { x ^ { 2 } } { x ^ { 2 } + 1 } d x$
Hint (a):
Express the numerator as $(x^2 + 1) – 1$ , then rewrite the fraction.

$\int _ { 1 } ^ { \infty } \frac { 1 } { e ^ { x } } d x$

$\int \operatorname { sec } ( 2 x ) \operatorname { tan } ( 2 x ) d x$