Mister Exam

Derivative of y=sqrt(ln(sin(3x)))

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

The graph:

from to

Piecewise:

The solution

You have entered [src]
  _______________
\/ log(sin(3*x)) 
log(sin(3x))\sqrt{\log{\left(\sin{\left(3 x \right)} \right)}}
d /  _______________\
--\\/ log(sin(3*x)) /
dx                   
ddxlog(sin(3x))\frac{d}{d x} \sqrt{\log{\left(\sin{\left(3 x \right)} \right)}}
Detail solution
  1. Let u=log(sin(3x))u = \log{\left(\sin{\left(3 x \right)} \right)}.

  2. Apply the power rule: u\sqrt{u} goes to 12u\frac{1}{2 \sqrt{u}}

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

    1. Let u=sin(3x)u = \sin{\left(3 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 ddxsin(3x)\frac{d}{d x} \sin{\left(3 x \right)}:

      1. Let u=3xu = 3 x.

      2. The derivative of sine is cosine:

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

      3. Then, apply the chain rule. Multiply by ddx3x\frac{d}{d x} 3 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: 33

        The result of the chain rule is:

        3cos(3x)3 \cos{\left(3 x \right)}

      The result of the chain rule is:

      3cos(3x)sin(3x)\frac{3 \cos{\left(3 x \right)}}{\sin{\left(3 x \right)}}

    The result of the chain rule is:

    3cos(3x)2log(sin(3x))sin(3x)\frac{3 \cos{\left(3 x \right)}}{2 \sqrt{\log{\left(\sin{\left(3 x \right)} \right)}} \sin{\left(3 x \right)}}

  4. Now simplify:

    32log(sin(3x))tan(3x)\frac{3}{2 \sqrt{\log{\left(\sin{\left(3 x \right)} \right)}} \tan{\left(3 x \right)}}


The answer is:

32log(sin(3x))tan(3x)\frac{3}{2 \sqrt{\log{\left(\sin{\left(3 x \right)} \right)}} \tan{\left(3 x \right)}}

The graph
02468-8-6-4-2-10100.02-0.02
The first derivative [src]
         3*cos(3*x)         
----------------------------
    _______________         
2*\/ log(sin(3*x)) *sin(3*x)
3cos(3x)2log(sin(3x))sin(3x)\frac{3 \cos{\left(3 x \right)}}{2 \sqrt{\log{\left(\sin{\left(3 x \right)} \right)}} \sin{\left(3 x \right)}}
The second derivative [src]
   /         2                  2            \
   |    2*cos (3*x)          cos (3*x)       |
-9*|2 + ----------- + -----------------------|
   |        2                          2     |
   \     sin (3*x)    log(sin(3*x))*sin (3*x)/
----------------------------------------------
                 _______________              
             4*\/ log(sin(3*x))               
9(2+2cos2(3x)sin2(3x)+cos2(3x)log(sin(3x))sin2(3x))4log(sin(3x))- \frac{9 \cdot \left(2 + \frac{2 \cos^{2}{\left(3 x \right)}}{\sin^{2}{\left(3 x \right)}} + \frac{\cos^{2}{\left(3 x \right)}}{\log{\left(\sin{\left(3 x \right)} \right)} \sin^{2}{\left(3 x \right)}}\right)}{4 \sqrt{\log{\left(\sin{\left(3 x \right)} \right)}}}
The third derivative [src]
   /                         2                    2                           2             \         
   |           3          cos (3*x)          3*cos (3*x)                 3*cos (3*x)        |         
27*|1 + --------------- + --------- + ------------------------- + --------------------------|*cos(3*x)
   |    4*log(sin(3*x))      2                           2             2              2     |         
   \                      sin (3*x)   4*log(sin(3*x))*sin (3*x)   8*log (sin(3*x))*sin (3*x)/         
------------------------------------------------------------------------------------------------------
                                        _______________                                               
                                      \/ log(sin(3*x)) *sin(3*x)                                      
27(1+cos2(3x)sin2(3x)+34log(sin(3x))+3cos2(3x)4log(sin(3x))sin2(3x)+3cos2(3x)8log(sin(3x))2sin2(3x))cos(3x)log(sin(3x))sin(3x)\frac{27 \cdot \left(1 + \frac{\cos^{2}{\left(3 x \right)}}{\sin^{2}{\left(3 x \right)}} + \frac{3}{4 \log{\left(\sin{\left(3 x \right)} \right)}} + \frac{3 \cos^{2}{\left(3 x \right)}}{4 \log{\left(\sin{\left(3 x \right)} \right)} \sin^{2}{\left(3 x \right)}} + \frac{3 \cos^{2}{\left(3 x \right)}}{8 \log{\left(\sin{\left(3 x \right)} \right)}^{2} \sin^{2}{\left(3 x \right)}}\right) \cos{\left(3 x \right)}}{\sqrt{\log{\left(\sin{\left(3 x \right)} \right)}} \sin{\left(3 x \right)}}
The graph
Derivative of y=sqrt(ln(sin(3x)))