Find the derivative of the constant function `f(x) = a`for a fixed real number a.

Explanation

To find the derivative of the constant function \( f(x) = a \) for a fixed real number \( a \), we will use the first principles of derivatives.

### Step-by-step Solution:

1. **Understanding the Derivative Definition**:
The derivative of a function \( f(x) \) at a point \( x \) is defined as:
\[
f'(x) = \lim_{h \to 0} \frac{f(x + h) - f(x)}{h}
...