Differentiate `sin^(2)x` w.r.t. `e^(cosx).`

Explanation

To differentiate \( \sin^2 x \) with respect to \( e^{\cos x} \), we can use the chain rule. Let's denote:

- \( u = \sin^2 x \)
- \( v = e^{\cos x} \)

We want to find \( \frac{du}{dv} \). By the chain rule, we have:

\[
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