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log(cos(5*x))^(2)

Derivative of log(cos(5*x))^(2)

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

You have entered [src]
   2          
log (cos(5*x))
log(cos(5x))2\log{\left(\cos{\left(5 x \right)} \right)}^{2}
d /   2          \
--\log (cos(5*x))/
dx                
ddxlog(cos(5x))2\frac{d}{d x} \log{\left(\cos{\left(5 x \right)} \right)}^{2}
Detail solution
  1. Let u=log(cos(5x))u = \log{\left(\cos{\left(5 x \right)} \right)}.

  2. Apply the power rule: u2u^{2} goes to 2u2 u

  3. Then, apply the chain rule. Multiply by ddxlog(cos(5x))\frac{d}{d x} \log{\left(\cos{\left(5 x \right)} \right)}:

    1. Let u=cos(5x)u = \cos{\left(5 x \right)}.

    2. The derivative of log(u)\log{\left(u \right)} is 1u\frac{1}{u}.

    3. Then, apply the chain rule. Multiply by ddxcos(5x)\frac{d}{d x} \cos{\left(5 x \right)}:

      1. Let u=5xu = 5 x.

      2. The derivative of cosine is negative sine:

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

      3. Then, apply the chain rule. Multiply by ddx5x\frac{d}{d x} 5 x:

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

          1. Apply the power rule: xx goes to 11

          So, the result is: 55

        The result of the chain rule is:

        5sin(5x)- 5 \sin{\left(5 x \right)}

      The result of the chain rule is:

      5sin(5x)cos(5x)- \frac{5 \sin{\left(5 x \right)}}{\cos{\left(5 x \right)}}

    The result of the chain rule is:

    10log(cos(5x))sin(5x)cos(5x)- \frac{10 \log{\left(\cos{\left(5 x \right)} \right)} \sin{\left(5 x \right)}}{\cos{\left(5 x \right)}}

  4. Now simplify:

    10log(cos(5x))tan(5x)- 10 \log{\left(\cos{\left(5 x \right)} \right)} \tan{\left(5 x \right)}


The answer is:

10log(cos(5x))tan(5x)- 10 \log{\left(\cos{\left(5 x \right)} \right)} \tan{\left(5 x \right)}

The graph
02468-8-6-4-2-1010-10001000
The first derivative [src]
-10*log(cos(5*x))*sin(5*x)
--------------------------
         cos(5*x)         
10log(cos(5x))sin(5x)cos(5x)- \frac{10 \log{\left(\cos{\left(5 x \right)} \right)} \sin{\left(5 x \right)}}{\cos{\left(5 x \right)}}
The second derivative [src]
   /                    2           2                   \
   |                 sin (5*x)   sin (5*x)*log(cos(5*x))|
50*|-log(cos(5*x)) + --------- - -----------------------|
   |                    2                  2            |
   \                 cos (5*x)          cos (5*x)       /
50(log(cos(5x))sin2(5x)cos2(5x)log(cos(5x))+sin2(5x)cos2(5x))50 \left(- \frac{\log{\left(\cos{\left(5 x \right)} \right)} \sin^{2}{\left(5 x \right)}}{\cos^{2}{\left(5 x \right)}} - \log{\left(\cos{\left(5 x \right)} \right)} + \frac{\sin^{2}{\left(5 x \right)}}{\cos^{2}{\left(5 x \right)}}\right)
The third derivative [src]
    /                           2             2                   \         
    |                      3*sin (5*x)   2*sin (5*x)*log(cos(5*x))|         
250*|3 - 2*log(cos(5*x)) + ----------- - -------------------------|*sin(5*x)
    |                          2                    2             |         
    \                       cos (5*x)            cos (5*x)        /         
----------------------------------------------------------------------------
                                  cos(5*x)                                  
250(2log(cos(5x))sin2(5x)cos2(5x)2log(cos(5x))+3sin2(5x)cos2(5x)+3)sin(5x)cos(5x)\frac{250 \left(- \frac{2 \log{\left(\cos{\left(5 x \right)} \right)} \sin^{2}{\left(5 x \right)}}{\cos^{2}{\left(5 x \right)}} - 2 \log{\left(\cos{\left(5 x \right)} \right)} + \frac{3 \sin^{2}{\left(5 x \right)}}{\cos^{2}{\left(5 x \right)}} + 3\right) \sin{\left(5 x \right)}}{\cos{\left(5 x \right)}}
The graph
Derivative of log(cos(5*x))^(2)