Sr Examen

Derivada de x*exp(-x)ln(tg(x))

Función f() - derivada -er orden en el punto
v

Gráfico:

interior superior

Definida a trozos:

Solución

Ha introducido [src]
   -x            
x*e  *log(tan(x))
xexlog(tan(x))x e^{- x} \log{\left(\tan{\left(x \right)} \right)}
(x*exp(-x))*log(tan(x))
Solución detallada
  1. 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)=xlog(tan(x))f{\left(x \right)} = x \log{\left(\tan{\left(x \right)} \right)} y g(x)=exg{\left(x \right)} = e^{x}.

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

    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)}

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

    1. Derivado exe^{x} es.

    Ahora aplicamos la regla de la derivada de una divesión:

    (xexlog(tan(x))+(x(sin2(x)+cos2(x))cos2(x)tan(x)+log(tan(x)))ex)e2x\left(- x e^{x} \log{\left(\tan{\left(x \right)} \right)} + \left(\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)}\right) e^{x}\right) e^{- 2 x}

  2. Simplificamos:

    (xlog(tan(x))+2xsin(2x)+log(tan(x)))ex\left(- x \log{\left(\tan{\left(x \right)} \right)} + \frac{2 x}{\sin{\left(2 x \right)}} + \log{\left(\tan{\left(x \right)} \right)}\right) e^{- x}


Respuesta:

(xlog(tan(x))+2xsin(2x)+log(tan(x)))ex\left(- x \log{\left(\tan{\left(x \right)} \right)} + \frac{2 x}{\sin{\left(2 x \right)}} + \log{\left(\tan{\left(x \right)} \right)}\right) e^{- x}

Gráfica
02468-8-6-4-2-1010-50000005000000
Primera derivada [src]
                                /       2   \  -x
/     -x    -x\               x*\1 + tan (x)/*e  
\- x*e   + e  /*log(tan(x)) + -------------------
                                     tan(x)      
x(tan2(x)+1)extan(x)+(xex+ex)log(tan(x))\frac{x \left(\tan^{2}{\left(x \right)} + 1\right) e^{- x}}{\tan{\left(x \right)}} + \left(- x e^{- x} + e^{- x}\right) \log{\left(\tan{\left(x \right)} \right)}
Segunda derivada [src]
/  /                             2\                                                  \    
|  |                /       2   \ |                            /       2   \         |    
|  |         2      \1 + tan (x)/ |                          2*\1 + tan (x)/*(-1 + x)|  -x
|x*|2 + 2*tan (x) - --------------| + (-2 + x)*log(tan(x)) - ------------------------|*e  
|  |                      2       |                                   tan(x)         |    
\  \                   tan (x)    /                                                  /    
(x((tan2(x)+1)2tan2(x)+2tan2(x)+2)+(x2)log(tan(x))2(x1)(tan2(x)+1)tan(x))ex\left(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) + \left(x - 2\right) \log{\left(\tan{\left(x \right)} \right)} - \frac{2 \left(x - 1\right) \left(\tan^{2}{\left(x \right)} + 1\right)}{\tan{\left(x \right)}}\right) e^{- x}
Tercera derivada [src]
/                                   /                             2\                     /                        2                  \                           \    
|                                   |                /       2   \ |                     |           /       2   \      /       2   \|     /       2   \         |    
|                                   |         2      \1 + tan (x)/ |       /       2   \ |           \1 + tan (x)/    2*\1 + tan (x)/|   3*\1 + tan (x)/*(-2 + x)|  -x
|-(-3 + x)*log(tan(x)) - 3*(-1 + x)*|2 + 2*tan (x) - --------------| + 2*x*\1 + tan (x)/*|2*tan(x) + -------------- - ---------------| + ------------------------|*e  
|                                   |                      2       |                     |                 3               tan(x)    |            tan(x)         |    
\                                   \                   tan (x)    /                     \              tan (x)                      /                           /    
(2x(tan2(x)+1)((tan2(x)+1)2tan3(x)2(tan2(x)+1)tan(x)+2tan(x))(x3)log(tan(x))+3(x2)(tan2(x)+1)tan(x)3(x1)((tan2(x)+1)2tan2(x)+2tan2(x)+2))ex\left(2 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) - \left(x - 3\right) \log{\left(\tan{\left(x \right)} \right)} + \frac{3 \left(x - 2\right) \left(\tan^{2}{\left(x \right)} + 1\right)}{\tan{\left(x \right)}} - 3 \left(x - 1\right) \left(- \frac{\left(\tan^{2}{\left(x \right)} + 1\right)^{2}}{\tan^{2}{\left(x \right)}} + 2 \tan^{2}{\left(x \right)} + 2\right)\right) e^{- x}
Gráfico
Derivada de x*exp(-x)ln(tg(x))