Sr Examen

Derivada de y=x³cos(x)sin(x)

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

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Solución

Ha introducido [src]
 3              
x *cos(x)*sin(x)
x3cos(x)sin(x)x^{3} \cos{\left(x \right)} \sin{\left(x \right)}
(x^3*cos(x))*sin(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)=x3cos(x)f{\left(x \right)} = x^{3} \cos{\left(x \right)}; calculamos 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)=x3f{\left(x \right)} = x^{3}; calculamos ddxf(x)\frac{d}{d x} f{\left(x \right)}:

      1. Según el principio, aplicamos: x3x^{3} tenemos 3x23 x^{2}

      g(x)=cos(x)g{\left(x \right)} = \cos{\left(x \right)}; calculamos 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)}

      Como resultado de: x3sin(x)+3x2cos(x)- x^{3} \sin{\left(x \right)} + 3 x^{2} \cos{\left(x \right)}

    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: x3cos2(x)+(x3sin(x)+3x2cos(x))sin(x)x^{3} \cos^{2}{\left(x \right)} + \left(- x^{3} \sin{\left(x \right)} + 3 x^{2} \cos{\left(x \right)}\right) \sin{\left(x \right)}

  2. Simplificamos:

    x2(xcos(2x)+3sin(2x)2)x^{2} \left(x \cos{\left(2 x \right)} + \frac{3 \sin{\left(2 x \right)}}{2}\right)


Respuesta:

x2(xcos(2x)+3sin(2x)2)x^{2} \left(x \cos{\left(2 x \right)} + \frac{3 \sin{\left(2 x \right)}}{2}\right)

Gráfica
02468-8-6-4-2-1010-20002000
Primera derivada [src]
 3    2      /   3             2       \       
x *cos (x) + \- x *sin(x) + 3*x *cos(x)/*sin(x)
x3cos2(x)+(x3sin(x)+3x2cos(x))sin(x)x^{3} \cos^{2}{\left(x \right)} + \left(- x^{3} \sin{\left(x \right)} + 3 x^{2} \cos{\left(x \right)}\right) \sin{\left(x \right)}
Segunda derivada [src]
   //             2                    \           2                                                  \
-x*\\-6*cos(x) + x *cos(x) + 6*x*sin(x)/*sin(x) + x *cos(x)*sin(x) + 2*x*(-3*cos(x) + x*sin(x))*cos(x)/
x(x2sin(x)cos(x)+2x(xsin(x)3cos(x))cos(x)+(x2cos(x)+6xsin(x)6cos(x))sin(x))- x \left(x^{2} \sin{\left(x \right)} \cos{\left(x \right)} + 2 x \left(x \sin{\left(x \right)} - 3 \cos{\left(x \right)}\right) \cos{\left(x \right)} + \left(x^{2} \cos{\left(x \right)} + 6 x \sin{\left(x \right)} - 6 \cos{\left(x \right)}\right) \sin{\left(x \right)}\right)
Tercera derivada [src]
/            3                           2       \           3    2          /             2                    \             2                              
\6*cos(x) + x *sin(x) - 18*x*sin(x) - 9*x *cos(x)/*sin(x) - x *cos (x) - 3*x*\-6*cos(x) + x *cos(x) + 6*x*sin(x)/*cos(x) + 3*x *(-3*cos(x) + x*sin(x))*sin(x)
x3cos2(x)+3x2(xsin(x)3cos(x))sin(x)3x(x2cos(x)+6xsin(x)6cos(x))cos(x)+(x3sin(x)9x2cos(x)18xsin(x)+6cos(x))sin(x)- x^{3} \cos^{2}{\left(x \right)} + 3 x^{2} \left(x \sin{\left(x \right)} - 3 \cos{\left(x \right)}\right) \sin{\left(x \right)} - 3 x \left(x^{2} \cos{\left(x \right)} + 6 x \sin{\left(x \right)} - 6 \cos{\left(x \right)}\right) \cos{\left(x \right)} + \left(x^{3} \sin{\left(x \right)} - 9 x^{2} \cos{\left(x \right)} - 18 x \sin{\left(x \right)} + 6 \cos{\left(x \right)}\right) \sin{\left(x \right)}
Gráfico
Derivada de y=x³cos(x)sin(x)