Differentiate `cot (2x+1)` from the first principle.

Explanation

To differentiate \( y = \cot(2x + 1) \) from the first principle, we will follow these steps:

### Step 1: Write the definition of the derivative
The derivative of a function \( y \) at a point \( x \) can be defined using the first principle as:
\[ \frac{dy}{dx} = \lim_{\Delta x \to 0} \frac{y(x + \Delta x) - y(x)}{\Delta x} \]

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