Find an antiderivative of 3(3x + 1)5.
First we find the indefinite integral of 3(3x + 1)5. Let u = 3x + 1 and u' = 3. Then
This is the family of all antiderivatives of 3(3x + 1)5. To get one antiderivative, we pick a value of C. The simplest choice is C = 0. This gives us the antiderivative