# Math Help - Using substitution rule

1. ## Using substitution rule

How would I use substitution to prove one element is the derivative of another for this problem: ʃ12(x^3+x)^4 (3x^2+1)dx

2. Originally Posted by whboutbob1223
How would I use substitution to prove one element is the derivative of another for this problem: ʃ12(x^3+x)^4 (3x^2+1)dx
$u = x^3+x$

$du = 3x^2+1 \, dx$