Derivative of e^(2-x)

1. Let $u = 2 - x$.

2. The derivative of $e^{u}$ is itself.

3. Then, apply the chain rule. Multiply by $\frac{d}{d x} \left(2 - x\right)$:

   1. Differentiate $2 - x$ term by term:

      1. The derivative of the constant $2$ is zero.

      2. The derivative of a constant times a function is the constant times the derivative of the function.

         1. Apply the power rule: $x$ goes to $1$

         So, the result is: $-1$

      The result is: $-1$

   The result of the chain rule is:

   $$- e^{2 - x}$$

The answer is:

$$- e^{2 - x}$$