# Thread: Diff Eq with 'u' Substitution

1. ## Diff Eq with 'u' Substitution

Hello I am having some trouble solving this equation, if anyone could shed some insight on what to do with the problem for the u substitution and perhaps the rest of the problem. Every online integrator seems to make the t^2 disappear and I can't figure out why.

2. ## Re: Diff Eq with 'u' Substitution

$u=t^3 \rightarrow t=u^{1/3}$ and $du=3t^2dt \rightarrow dt=\frac{du}{3t^2}=\frac{du}{3u^{2/3}}$ Now substitute in the integral