`intx^3sinx^4 dx on R`

Explanation

To evaluate the integral \( I = \int x^3 \sin(x^4) \, dx \), we will use substitution and integration techniques. Here are the steps:

### Step 1: Set up the integral
We start with the integral:
\[ I = \int x^3 \sin(x^4) \, dx \]

...