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Derivative of sin^2(x/2)*ctg(x/2)

Function f() - derivative -N order at the point
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The solution

You have entered [src]
   2/x\    /x\
sin |-|*cot|-|
    \2/    \2/
$$\sin^{2}{\left(\frac{x}{2} \right)} \cot{\left(\frac{x}{2} \right)}$$
sin(x/2)^2*cot(x/2)
Detail solution
  1. Apply the product rule:

    ; to find :

    1. Let .

    2. Apply the power rule: goes to

    3. Then, apply the chain rule. Multiply by :

      1. Let .

      2. The derivative of sine is cosine:

      3. Then, apply the chain rule. Multiply by :

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

          1. Apply the power rule: goes to

          So, the result is:

        The result of the chain rule is:

      The result of the chain rule is:

    ; to find :

    1. There are multiple ways to do this derivative.

      Method #1

      1. Rewrite the function to be differentiated:

      2. Let .

      3. Apply the power rule: goes to

      4. Then, apply the chain rule. Multiply by :

        1. Rewrite the function to be differentiated:

        2. Apply the quotient rule, which is:

          and .

          To find :

          1. Let .

          2. The derivative of sine is cosine:

          3. Then, apply the chain rule. Multiply by :

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

              1. Apply the power rule: goes to

              So, the result is:

            The result of the chain rule is:

          To find :

          1. Let .

          2. The derivative of cosine is negative sine:

          3. Then, apply the chain rule. Multiply by :

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

              1. Apply the power rule: goes to

              So, the result is:

            The result of the chain rule is:

          Now plug in to the quotient rule:

        The result of the chain rule is:

      Method #2

      1. Rewrite the function to be differentiated:

      2. Apply the quotient rule, which is:

        and .

        To find :

        1. Let .

        2. The derivative of cosine is negative sine:

        3. Then, apply the chain rule. Multiply by :

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

            1. Apply the power rule: goes to

            So, the result is:

          The result of the chain rule is:

        To find :

        1. Let .

        2. The derivative of sine is cosine:

        3. Then, apply the chain rule. Multiply by :

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

            1. Apply the power rule: goes to

            So, the result is:

          The result of the chain rule is:

        Now plug in to the quotient rule:

    The result is:

  2. Now simplify:


The answer is:

The graph
The first derivative [src]
        /         2/x\\                       
        |      cot |-||                       
   2/x\ |  1       \2/|      /x\    /x\    /x\
sin |-|*|- - - -------| + cos|-|*cot|-|*sin|-|
    \2/ \  2      2   /      \2/    \2/    \2/
$$\left(- \frac{\cot^{2}{\left(\frac{x}{2} \right)}}{2} - \frac{1}{2}\right) \sin^{2}{\left(\frac{x}{2} \right)} + \sin{\left(\frac{x}{2} \right)} \cos{\left(\frac{x}{2} \right)} \cot{\left(\frac{x}{2} \right)}$$
The second derivative [src]
  /   2/x\      2/x\\    /x\      2/x\ /       2/x\\    /x\                              
  |sin |-| - cos |-||*cot|-|   sin |-|*|1 + cot |-||*cot|-|                              
  \    \2/       \2//    \2/       \2/ \        \2//    \2/   /       2/x\\    /x\    /x\
- -------------------------- + ---------------------------- - |1 + cot |-||*cos|-|*sin|-|
              2                             2                 \        \2//    \2/    \2/
$$- \frac{\left(\sin^{2}{\left(\frac{x}{2} \right)} - \cos^{2}{\left(\frac{x}{2} \right)}\right) \cot{\left(\frac{x}{2} \right)}}{2} + \frac{\left(\cot^{2}{\left(\frac{x}{2} \right)} + 1\right) \sin^{2}{\left(\frac{x}{2} \right)} \cot{\left(\frac{x}{2} \right)}}{2} - \left(\cot^{2}{\left(\frac{x}{2} \right)} + 1\right) \sin{\left(\frac{x}{2} \right)} \cos{\left(\frac{x}{2} \right)}$$
The third derivative [src]
  /       2/x\\ /   2/x\      2/x\\                             2/x\ /       2/x\\ /         2/x\\     /       2/x\\    /x\    /x\    /x\
3*|1 + cot |-||*|sin |-| - cos |-||                          sin |-|*|1 + cot |-||*|1 + 3*cot |-||   3*|1 + cot |-||*cos|-|*cot|-|*sin|-|
  \        \2// \    \2/       \2//      /x\    /x\    /x\       \2/ \        \2// \          \2//     \        \2//    \2/    \2/    \2/
----------------------------------- - cos|-|*cot|-|*sin|-| - ------------------------------------- + ------------------------------------
                 4                       \2/    \2/    \2/                     4                                      2                  
$$\frac{3 \left(\sin^{2}{\left(\frac{x}{2} \right)} - \cos^{2}{\left(\frac{x}{2} \right)}\right) \left(\cot^{2}{\left(\frac{x}{2} \right)} + 1\right)}{4} - \frac{\left(\cot^{2}{\left(\frac{x}{2} \right)} + 1\right) \left(3 \cot^{2}{\left(\frac{x}{2} \right)} + 1\right) \sin^{2}{\left(\frac{x}{2} \right)}}{4} + \frac{3 \left(\cot^{2}{\left(\frac{x}{2} \right)} + 1\right) \sin{\left(\frac{x}{2} \right)} \cos{\left(\frac{x}{2} \right)} \cot{\left(\frac{x}{2} \right)}}{2} - \sin{\left(\frac{x}{2} \right)} \cos{\left(\frac{x}{2} \right)} \cot{\left(\frac{x}{2} \right)}$$