Derivative of tan(3.14*x)

1. Rewrite the function to be differentiated:

   $$\tan{\left(\frac{157 x}{50} \right)} = \frac{\sin{\left(\frac{157 x}{50} \right)}}{\cos{\left(\frac{157 x}{50} \right)}}$$

2. Apply the quotient rule, which is:

   $$\frac{d}{d x} \frac{f{\left(x \right)}}{g{\left(x \right)}} = \frac{- f{\left(x \right)} \frac{d}{d x} g{\left(x \right)} + g{\left(x \right)} \frac{d}{d x} f{\left(x \right)}}{g^{2}{\left(x \right)}}$$

   $f{\left(x \right)} = \sin{\left(\frac{157 x}{50} \right)}$ and $g{\left(x \right)} = \cos{\left(\frac{157 x}{50} \right)}$.

   To find $\frac{d}{d x} f{\left(x \right)}$:

   1. Let $u = \frac{157 x}{50}$.

   2. The derivative of sine is cosine:

      $$\frac{d}{d u} \sin{\left(u \right)} = \cos{\left(u \right)}$$

   3. Then, apply the chain rule. Multiply by $\frac{d}{d x} \frac{157 x}{50}$:

      1. 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: $\frac{157}{50}$

      The result of the chain rule is:

      $$\frac{157 \cos{\left(\frac{157 x}{50} \right)}}{50}$$

   To find $\frac{d}{d x} g{\left(x \right)}$:

   1. Let $u = \frac{157 x}{50}$.

   2. The derivative of cosine is negative sine:

      $$\frac{d}{d u} \cos{\left(u \right)} = - \sin{\left(u \right)}$$

   3. Then, apply the chain rule. Multiply by $\frac{d}{d x} \frac{157 x}{50}$:

      1. 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: $\frac{157}{50}$

      The result of the chain rule is:

      $$- \frac{157 \sin{\left(\frac{157 x}{50} \right)}}{50}$$

   Now plug in to the quotient rule:

   $\frac{\frac{157 \sin^{2}{\left(\frac{157 x}{50} \right)}}{50} + \frac{157 \cos^{2}{\left(\frac{157 x}{50} \right)}}{50}}{\cos^{2}{\left(\frac{157 x}{50} \right)}}$

3. Now simplify:

   $$\frac{157}{50 \cos^{2}{\left(\frac{157 x}{50} \right)}}$$

The answer is:

$$\frac{157}{50 \cos^{2}{\left(\frac{157 x}{50} \right)}}$$