Sr Examen

Derivada de x*sin(x)/sin(x)

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

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Definida a trozos:

Solución

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

    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. La derivada del seno es igual al coseno:

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

    Ahora aplicamos la regla de la derivada de una divesión:

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

  2. Simplificamos:

    11


Respuesta:

11

Gráfica
02468-8-6-4-2-1010-2020
Primera derivada [src]
x*cos(x) + sin(x)   x*cos(x)
----------------- - --------
      sin(x)         sin(x) 
xcos(x)sin(x)+xcos(x)+sin(x)sin(x)- \frac{x \cos{\left(x \right)}}{\sin{\left(x \right)}} + \frac{x \cos{\left(x \right)} + \sin{\left(x \right)}}{\sin{\left(x \right)}}
Segunda derivada [src]
  /         2   \                                                      
  |    2*cos (x)|   -2*cos(x) + x*sin(x)   2*(x*cos(x) + sin(x))*cos(x)
x*|1 + ---------| - -------------------- - ----------------------------
  |        2    |          sin(x)                       2              
  \     sin (x) /                                    sin (x)           
x(1+2cos2(x)sin2(x))xsin(x)2cos(x)sin(x)2(xcos(x)+sin(x))cos(x)sin2(x)x \left(1 + \frac{2 \cos^{2}{\left(x \right)}}{\sin^{2}{\left(x \right)}}\right) - \frac{x \sin{\left(x \right)} - 2 \cos{\left(x \right)}}{\sin{\left(x \right)}} - \frac{2 \left(x \cos{\left(x \right)} + \sin{\left(x \right)}\right) \cos{\left(x \right)}}{\sin^{2}{\left(x \right)}}
Tercera derivada [src]
                         /         2   \                         /         2   \                                         
                         |    2*cos (x)|                         |    6*cos (x)|          3*(-2*cos(x) + x*sin(x))*cos(x)
-3*sin(x) - x*cos(x) + 3*|1 + ---------|*(x*cos(x) + sin(x)) - x*|5 + ---------|*cos(x) + -------------------------------
                         |        2    |                         |        2    |                       sin(x)            
                         \     sin (x) /                         \     sin (x) /                                         
-------------------------------------------------------------------------------------------------------------------------
                                                          sin(x)                                                         
x(5+6cos2(x)sin2(x))cos(x)xcos(x)+3(1+2cos2(x)sin2(x))(xcos(x)+sin(x))+3(xsin(x)2cos(x))cos(x)sin(x)3sin(x)sin(x)\frac{- x \left(5 + \frac{6 \cos^{2}{\left(x \right)}}{\sin^{2}{\left(x \right)}}\right) \cos{\left(x \right)} - x \cos{\left(x \right)} + 3 \left(1 + \frac{2 \cos^{2}{\left(x \right)}}{\sin^{2}{\left(x \right)}}\right) \left(x \cos{\left(x \right)} + \sin{\left(x \right)}\right) + \frac{3 \left(x \sin{\left(x \right)} - 2 \cos{\left(x \right)}\right) \cos{\left(x \right)}}{\sin{\left(x \right)}} - 3 \sin{\left(x \right)}}{\sin{\left(x \right)}}
Gráfico
Derivada de x*sin(x)/sin(x)