Sr Examen

Derivada de xln(tgx)

Función f() - derivada -er orden en el punto
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Gráfico:

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Solución

Ha introducido [src]
x*log(tan(x))
xlog(tan(x))x \log{\left(\tan{\left(x \right)} \right)}
x*log(tan(x))
Solución detallada
  1. Se aplica la regla de la derivada de una multiplicación:

    ddxf(x)g(x)=f(x)ddxg(x)+g(x)ddxf(x)\frac{d}{d x} f{\left(x \right)} g{\left(x \right)} = f{\left(x \right)} \frac{d}{d x} g{\left(x \right)} + g{\left(x \right)} \frac{d}{d x} f{\left(x \right)}

    f(x)=xf{\left(x \right)} = x; calculamos ddxf(x)\frac{d}{d x} f{\left(x \right)}:

    1. Según el principio, aplicamos: xx tenemos 11

    g(x)=log(tan(x))g{\left(x \right)} = \log{\left(\tan{\left(x \right)} \right)}; calculamos ddxg(x)\frac{d}{d x} g{\left(x \right)}:

    1. Sustituimos u=tan(x)u = \tan{\left(x \right)}.

    2. Derivado log(u)\log{\left(u \right)} es 1u\frac{1}{u}.

    3. Luego se aplica una cadena de reglas. Multiplicamos por ddxtan(x)\frac{d}{d x} \tan{\left(x \right)}:

      1. Reescribimos las funciones para diferenciar:

        tan(x)=sin(x)cos(x)\tan{\left(x \right)} = \frac{\sin{\left(x \right)}}{\cos{\left(x \right)}}

      2. Se aplica la regla de la derivada parcial:

        ddxf(x)g(x)=f(x)ddxg(x)+g(x)ddxf(x)g2(x)\frac{d}{d x} \frac{f{\left(x \right)}}{g{\left(x \right)}} = \frac{- f{\left(x \right)} \frac{d}{d x} g{\left(x \right)} + g{\left(x \right)} \frac{d}{d x} f{\left(x \right)}}{g^{2}{\left(x \right)}}

        f(x)=sin(x)f{\left(x \right)} = \sin{\left(x \right)} y g(x)=cos(x)g{\left(x \right)} = \cos{\left(x \right)}.

        Para calcular ddxf(x)\frac{d}{d x} f{\left(x \right)}:

        1. La derivada del seno es igual al coseno:

          ddxsin(x)=cos(x)\frac{d}{d x} \sin{\left(x \right)} = \cos{\left(x \right)}

        Para calcular ddxg(x)\frac{d}{d x} g{\left(x \right)}:

        1. La derivada del coseno es igual a menos el seno:

          ddxcos(x)=sin(x)\frac{d}{d x} \cos{\left(x \right)} = - \sin{\left(x \right)}

        Ahora aplicamos la regla de la derivada de una divesión:

        sin2(x)+cos2(x)cos2(x)\frac{\sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}{\cos^{2}{\left(x \right)}}

      Como resultado de la secuencia de reglas:

      sin2(x)+cos2(x)cos2(x)tan(x)\frac{\sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}{\cos^{2}{\left(x \right)} \tan{\left(x \right)}}

    Como resultado de: x(sin2(x)+cos2(x))cos2(x)tan(x)+log(tan(x))\frac{x \left(\sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}\right)}{\cos^{2}{\left(x \right)} \tan{\left(x \right)}} + \log{\left(\tan{\left(x \right)} \right)}

  2. Simplificamos:

    2xsin(2x)+log(tan(x))\frac{2 x}{\sin{\left(2 x \right)}} + \log{\left(\tan{\left(x \right)} \right)}


Respuesta:

2xsin(2x)+log(tan(x))\frac{2 x}{\sin{\left(2 x \right)}} + \log{\left(\tan{\left(x \right)} \right)}

Gráfica
02468-8-6-4-2-1010-500500
Primera derivada [src]
  /       2   \              
x*\1 + tan (x)/              
--------------- + log(tan(x))
     tan(x)                  
x(tan2(x)+1)tan(x)+log(tan(x))\frac{x \left(\tan^{2}{\left(x \right)} + 1\right)}{\tan{\left(x \right)}} + \log{\left(\tan{\left(x \right)} \right)}
Segunda derivada [src]
  /                             2\                  
  |                /       2   \ |     /       2   \
  |         2      \1 + tan (x)/ |   2*\1 + tan (x)/
x*|2 + 2*tan (x) - --------------| + ---------------
  |                      2       |        tan(x)    
  \                   tan (x)    /                  
x((tan2(x)+1)2tan2(x)+2tan2(x)+2)+2(tan2(x)+1)tan(x)x \left(- \frac{\left(\tan^{2}{\left(x \right)} + 1\right)^{2}}{\tan^{2}{\left(x \right)}} + 2 \tan^{2}{\left(x \right)} + 2\right) + \frac{2 \left(\tan^{2}{\left(x \right)} + 1\right)}{\tan{\left(x \right)}}
Tercera derivada [src]
                               2                     /                        2                  \
                  /       2   \                      |           /       2   \      /       2   \|
         2      3*\1 + tan (x)/        /       2   \ |           \1 + tan (x)/    2*\1 + tan (x)/|
6 + 6*tan (x) - ---------------- + 2*x*\1 + tan (x)/*|2*tan(x) + -------------- - ---------------|
                       2                             |                 3               tan(x)    |
                    tan (x)                          \              tan (x)                      /
2x(tan2(x)+1)((tan2(x)+1)2tan3(x)2(tan2(x)+1)tan(x)+2tan(x))3(tan2(x)+1)2tan2(x)+6tan2(x)+62 x \left(\tan^{2}{\left(x \right)} + 1\right) \left(\frac{\left(\tan^{2}{\left(x \right)} + 1\right)^{2}}{\tan^{3}{\left(x \right)}} - \frac{2 \left(\tan^{2}{\left(x \right)} + 1\right)}{\tan{\left(x \right)}} + 2 \tan{\left(x \right)}\right) - \frac{3 \left(\tan^{2}{\left(x \right)} + 1\right)^{2}}{\tan^{2}{\left(x \right)}} + 6 \tan^{2}{\left(x \right)} + 6
Gráfico
Derivada de xln(tgx)