Let .
The derivative of is itself.
Then, apply the chain rule. Multiply by :
Differentiate term by term:
The derivative of cosine is negative sine:
The derivative of is .
The result is:
The result of the chain rule is:
Now simplify:
The answer is:
/ / 1 \ /1 \\ cos(t) |(-1 + t*sin(t))*|- - + sin(t)| - t*|-- + cos(t)||*e | \ t / | 2 || \ \t //
/ 1 /2 \ /1 \ / 1 \ / 2 \ /1 \ \ cos(t) |- -- - cos(t) + t*|-- + sin(t)| + (-1 + t*sin(t))*|-- + cos(t)| + |- - + sin(t)|*\2*sin(t) + t*cos(t) - t*sin (t)/ + t*|-- + cos(t)|*sin(t)|*e | 2 | 3 | | 2 | \ t / | 2 | | \ t \t / \t / \t / /