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Derivative of 3lnsqrt(cos(2*x))

Function f() - derivative -N order at the point
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
     /  __________\
3*log\\/ cos(2*x) /
$$3 \log{\left(\sqrt{\cos{\left(2 x \right)}} \right)}$$
3*log(sqrt(cos(2*x)))
Detail solution
  1. The derivative of a constant times a function is the constant times the derivative of the function.

    1. Let .

    2. The derivative of is .

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

      1. Let .

      2. Apply the power rule: goes to

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

        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:

        The result of the chain rule is:

      The result of the chain rule is:

    So, the result is:

  2. Now simplify:


The answer is:

The graph
The first derivative [src]
-3*sin(2*x)
-----------
  cos(2*x) 
$$- \frac{3 \sin{\left(2 x \right)}}{\cos{\left(2 x \right)}}$$
The second derivative [src]
   /       2     \
   |    sin (2*x)|
-6*|1 + ---------|
   |       2     |
   \    cos (2*x)/
$$- 6 \left(\frac{\sin^{2}{\left(2 x \right)}}{\cos^{2}{\left(2 x \right)}} + 1\right)$$
The third derivative [src]
    /       2     \         
    |    sin (2*x)|         
-24*|1 + ---------|*sin(2*x)
    |       2     |         
    \    cos (2*x)/         
----------------------------
          cos(2*x)          
$$- \frac{24 \left(\frac{\sin^{2}{\left(2 x \right)}}{\cos^{2}{\left(2 x \right)}} + 1\right) \sin{\left(2 x \right)}}{\cos{\left(2 x \right)}}$$