Now use u-substitution: let u = and du = dx, so 2du = dx, and substitute.
When you substitute back, you get
sin−1 + C
Example 6:
Again, use u-substitution. Let u = ex and du = ex dx, and substitute.
= tan−1 u + C
Then substitute back.
tan−1ex + C
Let’s do one last type that’s slightly more difficult. For this one, you need to remember how to complete
the square.
Example 7:
Complete the square in the denominator (your algebra teacher warned you about this).
x^2 + 4x + 5 = (x + 2)^2 + 1
Now rewrite the integral.