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Derivative of log5(cos(3x))^4

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

The graph:

from to

Piecewise:

The solution

You have entered [src]
               4
/log(cos(3*x))\ 
|-------------| 
\    log(5)   / 
$$\left(\frac{\log{\left(\cos{\left(3 x \right)} \right)}}{\log{\left(5 \right)}}\right)^{4}$$
(log(cos(3*x))/log(5))^4
Detail solution
  1. Let .

  2. Apply the power rule: goes to

  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. Let .

      2. The derivative of is .

      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:

      So, the result is:

    The result of the chain rule is:

  4. Now simplify:


The answer is:

The graph
The first derivative [src]
       4                   
    log (cos(3*x))         
-12*--------------*sin(3*x)
          4                
       log (5)             
---------------------------
   cos(3*x)*log(cos(3*x))  
$$- \frac{12 \frac{\log{\left(\cos{\left(3 x \right)} \right)}^{4}}{\log{\left(5 \right)}^{4}} \sin{\left(3 x \right)}}{\log{\left(\cos{\left(3 x \right)} \right)} \cos{\left(3 x \right)}}$$
The second derivative [src]
                  /                      2           2                   \
      2           |                 3*sin (3*x)   sin (3*x)*log(cos(3*x))|
36*log (cos(3*x))*|-log(cos(3*x)) + ----------- - -----------------------|
                  |                     2                   2            |
                  \                  cos (3*x)           cos (3*x)       /
--------------------------------------------------------------------------
                                    4                                     
                                 log (5)                                  
$$\frac{36 \left(- \frac{\log{\left(\cos{\left(3 x \right)} \right)} \sin^{2}{\left(3 x \right)}}{\cos^{2}{\left(3 x \right)}} - \log{\left(\cos{\left(3 x \right)} \right)} + \frac{3 \sin^{2}{\left(3 x \right)}}{\cos^{2}{\left(3 x \right)}}\right) \log{\left(\cos{\left(3 x \right)} \right)}^{2}}{\log{\left(5 \right)}^{4}}$$
The third derivative [src]
    /                                            2             2              2             2                   \                       
    |       2                               6*sin (3*x)   2*log (cos(3*x))*sin (3*x)   9*sin (3*x)*log(cos(3*x))|                       
108*|- 2*log (cos(3*x)) + 9*log(cos(3*x)) - ----------- - -------------------------- + -------------------------|*log(cos(3*x))*sin(3*x)
    |                                           2                    2                            2             |                       
    \                                        cos (3*x)            cos (3*x)                    cos (3*x)        /                       
----------------------------------------------------------------------------------------------------------------------------------------
                                                                        4                                                               
                                                            cos(3*x)*log (5)                                                            
$$\frac{108 \left(- \frac{2 \log{\left(\cos{\left(3 x \right)} \right)}^{2} \sin^{2}{\left(3 x \right)}}{\cos^{2}{\left(3 x \right)}} - 2 \log{\left(\cos{\left(3 x \right)} \right)}^{2} + \frac{9 \log{\left(\cos{\left(3 x \right)} \right)} \sin^{2}{\left(3 x \right)}}{\cos^{2}{\left(3 x \right)}} + 9 \log{\left(\cos{\left(3 x \right)} \right)} - \frac{6 \sin^{2}{\left(3 x \right)}}{\cos^{2}{\left(3 x \right)}}\right) \log{\left(\cos{\left(3 x \right)} \right)} \sin{\left(3 x \right)}}{\log{\left(5 \right)}^{4} \cos{\left(3 x \right)}}$$