Sr Examen

Derivada de (xsinx)/(1+tgx)

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

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Solución

Ha introducido [src]
 x*sin(x) 
----------
1 + tan(x)
xsin(x)tan(x)+1\frac{x \sin{\left(x \right)}}{\tan{\left(x \right)} + 1}
(x*sin(x))/(1 + 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)=xsin(x)f{\left(x \right)} = x \sin{\left(x \right)} y g(x)=tan(x)+1g{\left(x \right)} = \tan{\left(x \right)} + 1.

    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)=sin(x)g{\left(x \right)} = \sin{\left(x \right)}; calculamos ddxg(x)\frac{d}{d x} g{\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)}

      Como resultado de: xcos(x)+sin(x)x \cos{\left(x \right)} + \sin{\left(x \right)}

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

    1. diferenciamos tan(x)+1\tan{\left(x \right)} + 1 miembro por miembro:

      1. La derivada de una constante 11 es igual a cero.

      2. Reescribimos las funciones para diferenciar:

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

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

    Ahora aplicamos la regla de la derivada de una divesión:

    x(sin2(x)+cos2(x))sin(x)cos2(x)+(xcos(x)+sin(x))(tan(x)+1)(tan(x)+1)2\frac{- \frac{x \left(\sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}\right) \sin{\left(x \right)}}{\cos^{2}{\left(x \right)}} + \left(x \cos{\left(x \right)} + \sin{\left(x \right)}\right) \left(\tan{\left(x \right)} + 1\right)}{\left(\tan{\left(x \right)} + 1\right)^{2}}

  2. Simplificamos:

    xsin(x)+(xcos(x)+sin(x))(tan(x)+1)cos2(x)(tan(x)+1)2cos2(x)\frac{- x \sin{\left(x \right)} + \left(x \cos{\left(x \right)} + \sin{\left(x \right)}\right) \left(\tan{\left(x \right)} + 1\right) \cos^{2}{\left(x \right)}}{\left(\tan{\left(x \right)} + 1\right)^{2} \cos^{2}{\left(x \right)}}


Respuesta:

xsin(x)+(xcos(x)+sin(x))(tan(x)+1)cos2(x)(tan(x)+1)2cos2(x)\frac{- x \sin{\left(x \right)} + \left(x \cos{\left(x \right)} + \sin{\left(x \right)}\right) \left(\tan{\left(x \right)} + 1\right) \cos^{2}{\left(x \right)}}{\left(\tan{\left(x \right)} + 1\right)^{2} \cos^{2}{\left(x \right)}}

Gráfica
02468-8-6-4-2-1010-1000010000
Primera derivada [src]
                      /        2   \       
x*cos(x) + sin(x)   x*\-1 - tan (x)/*sin(x)
----------------- + -----------------------
    1 + tan(x)                       2     
                         (1 + tan(x))      
x(tan2(x)1)sin(x)(tan(x)+1)2+xcos(x)+sin(x)tan(x)+1\frac{x \left(- \tan^{2}{\left(x \right)} - 1\right) \sin{\left(x \right)}}{\left(\tan{\left(x \right)} + 1\right)^{2}} + \frac{x \cos{\left(x \right)} + \sin{\left(x \right)}}{\tan{\left(x \right)} + 1}
Segunda derivada [src]
 /                                                                               /         2            \       \ 
 |                                                                 /       2   \ |  1 + tan (x)         |       | 
 |                         /       2   \                       2*x*\1 + tan (x)/*|- ----------- + tan(x)|*sin(x)| 
 |                       2*\1 + tan (x)/*(x*cos(x) + sin(x))                     \   1 + tan(x)         /       | 
-|-2*cos(x) + x*sin(x) + ----------------------------------- + -------------------------------------------------| 
 \                                    1 + tan(x)                                   1 + tan(x)                   / 
------------------------------------------------------------------------------------------------------------------
                                                    1 + tan(x)                                                    
xsin(x)+2x(tan(x)tan2(x)+1tan(x)+1)(tan2(x)+1)sin(x)tan(x)+1+2(xcos(x)+sin(x))(tan2(x)+1)tan(x)+12cos(x)tan(x)+1- \frac{x \sin{\left(x \right)} + \frac{2 x \left(\tan{\left(x \right)} - \frac{\tan^{2}{\left(x \right)} + 1}{\tan{\left(x \right)} + 1}\right) \left(\tan^{2}{\left(x \right)} + 1\right) \sin{\left(x \right)}}{\tan{\left(x \right)} + 1} + \frac{2 \left(x \cos{\left(x \right)} + \sin{\left(x \right)}\right) \left(\tan^{2}{\left(x \right)} + 1\right)}{\tan{\left(x \right)} + 1} - 2 \cos{\left(x \right)}}{\tan{\left(x \right)} + 1}
Tercera derivada [src]
                                                                                                                                                 /                               2                         \       
                                                                                                                                                 |                  /       2   \      /       2   \       |       
                                                                                                    /         2            \       /       2   \ |         2      3*\1 + tan (x)/    6*\1 + tan (x)/*tan(x)|       
                                                                  /       2   \                     |  1 + tan (x)         |   2*x*\1 + tan (x)/*|1 + 3*tan (x) + ---------------- - ----------------------|*sin(x)
                         /       2   \                          6*\1 + tan (x)/*(x*cos(x) + sin(x))*|- ----------- + tan(x)|                     |                             2           1 + tan(x)      |       
                       3*\1 + tan (x)/*(-2*cos(x) + x*sin(x))                                       \   1 + tan(x)         /                     \                 (1 + tan(x))                            /       
-3*sin(x) - x*cos(x) + -------------------------------------- - ------------------------------------------------------------ - ------------------------------------------------------------------------------------
                                     1 + tan(x)                                          1 + tan(x)                                                                 1 + tan(x)                                     
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                     1 + tan(x)                                                                                                    
xcos(x)2x(tan2(x)+1)(3tan2(x)+16(tan2(x)+1)tan(x)tan(x)+1+3(tan2(x)+1)2(tan(x)+1)2)sin(x)tan(x)+1+3(xsin(x)2cos(x))(tan2(x)+1)tan(x)+16(xcos(x)+sin(x))(tan(x)tan2(x)+1tan(x)+1)(tan2(x)+1)tan(x)+13sin(x)tan(x)+1\frac{- x \cos{\left(x \right)} - \frac{2 x \left(\tan^{2}{\left(x \right)} + 1\right) \left(3 \tan^{2}{\left(x \right)} + 1 - \frac{6 \left(\tan^{2}{\left(x \right)} + 1\right) \tan{\left(x \right)}}{\tan{\left(x \right)} + 1} + \frac{3 \left(\tan^{2}{\left(x \right)} + 1\right)^{2}}{\left(\tan{\left(x \right)} + 1\right)^{2}}\right) \sin{\left(x \right)}}{\tan{\left(x \right)} + 1} + \frac{3 \left(x \sin{\left(x \right)} - 2 \cos{\left(x \right)}\right) \left(\tan^{2}{\left(x \right)} + 1\right)}{\tan{\left(x \right)} + 1} - \frac{6 \left(x \cos{\left(x \right)} + \sin{\left(x \right)}\right) \left(\tan{\left(x \right)} - \frac{\tan^{2}{\left(x \right)} + 1}{\tan{\left(x \right)} + 1}\right) \left(\tan^{2}{\left(x \right)} + 1\right)}{\tan{\left(x \right)} + 1} - 3 \sin{\left(x \right)}}{\tan{\left(x \right)} + 1}
Gráfico
Derivada de (xsinx)/(1+tgx)