# Using substitution rule

• Feb 17th 2010, 02:56 PM
whboutbob1223
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
• Feb 17th 2010, 03:09 PM
skeeter
Quote:

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

$u = x^3+x$

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