Derivative Arccos Sin
1. **Problem statement:** Find the derivative of the function $$y = \arccos\left(\sin\left(e^x\right)\right)$$.
2. **Recall the chain rule:** The derivative of $$\arccos u$$ with respect to $$x$$ is $$\frac{dy}{dx} = -\frac{1}{\sqrt{1-u^2}} \cdot \frac{du}{dx}$$.
3. **Identify the inner function:** Here, $$u = \sin\left(e^x\right)$$.
4. **Find the derivative of $$u$$:**
$$\frac{du}{dx} = \cos\left(e^x\right) \cdot \frac{d}{dx} e^x = \cos\left(e^x\right) \cdot e^x$$.
5. **Apply the chain rule:**
$$\frac{dy}{dx} = -\frac{1}{\sqrt{1-\sin^2\left(e^x\right)}} \cdot \cos\left(e^x\right) e^x$$.
6. **Simplify inside the square root:** Recall $$1-\sin^2(\theta) = \cos^2(\theta)$$, so
$$\sqrt{1-\sin^2\left(e^x\right)} = \sqrt{\cos^2\left(e^x\right)} = |\cos\left(e^x\right)|$$.
7. **Final simplified derivative:**
$$\frac{dy}{dx} = -\frac{\cos\left(e^x\right) e^x}{|\cos\left(e^x\right)|}$$.
This derivative can be written as
$$\boxed{\frac{dy}{dx} = -e^x \cdot \mathrm{sgn}\left(\cos\left(e^x\right)\right)}$$,
where $$\mathrm{sgn}$$ denotes the sign function capturing the absolute value division.