Sr Examen

Derivada de y=cosxsecx/cotx

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

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Solución

Ha introducido [src]
cos(x)*sec(x)
-------------
    cot(x)   
cos(x)sec(x)cot(x)\frac{\cos{\left(x \right)} \sec{\left(x \right)}}{\cot{\left(x \right)}}
(cos(x)*sec(x))/cot(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)=cos(x)sec(x)f{\left(x \right)} = \cos{\left(x \right)} \sec{\left(x \right)} y g(x)=cot(x)g{\left(x \right)} = \cot{\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)=cos(x)f{\left(x \right)} = \cos{\left(x \right)}; calculamos ddxf(x)\frac{d}{d x} f{\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)}

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

      1. Reescribimos las funciones para diferenciar:

        sec(x)=1cos(x)\sec{\left(x \right)} = \frac{1}{\cos{\left(x \right)}}

      2. Sustituimos u=cos(x)u = \cos{\left(x \right)}.

      3. Según el principio, aplicamos: 1u\frac{1}{u} tenemos 1u2- \frac{1}{u^{2}}

      4. Luego se aplica una cadena de reglas. Multiplicamos por ddxcos(x)\frac{d}{d x} \cos{\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 la secuencia de reglas:

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

      Como resultado de: sin(x)sec(x)+sin(x)cos(x)- \sin{\left(x \right)} \sec{\left(x \right)} + \frac{\sin{\left(x \right)}}{\cos{\left(x \right)}}

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

    1. Hay varias formas de calcular esta derivada.

      Method #1

      1. Reescribimos las funciones para diferenciar:

        cot(x)=1tan(x)\cot{\left(x \right)} = \frac{1}{\tan{\left(x \right)}}

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

      3. Según el principio, aplicamos: 1u\frac{1}{u} tenemos 1u2- \frac{1}{u^{2}}

      4. 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)tan2(x)- \frac{\sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}{\cos^{2}{\left(x \right)} \tan^{2}{\left(x \right)}}

      Method #2

      1. Reescribimos las funciones para diferenciar:

        cot(x)=cos(x)sin(x)\cot{\left(x \right)} = \frac{\cos{\left(x \right)}}{\sin{\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)=cos(x)f{\left(x \right)} = \cos{\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. 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)}

        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:

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

    Ahora aplicamos la regla de la derivada de una divesión:

    (sin(x)sec(x)+sin(x)cos(x))cot(x)+(sin2(x)+cos2(x))sec(x)cos(x)tan2(x)cot2(x)\frac{\left(- \sin{\left(x \right)} \sec{\left(x \right)} + \frac{\sin{\left(x \right)}}{\cos{\left(x \right)}}\right) \cot{\left(x \right)} + \frac{\left(\sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}\right) \sec{\left(x \right)}}{\cos{\left(x \right)} \tan^{2}{\left(x \right)}}}{\cot^{2}{\left(x \right)}}

  2. Simplificamos:

    1cos2(x)\frac{1}{\cos^{2}{\left(x \right)}}


Respuesta:

1cos2(x)\frac{1}{\cos^{2}{\left(x \right)}}

Gráfica
02468-8-6-4-2-1010-10001000
Primera derivada [src]
                                        /       2   \              
-sec(x)*sin(x) + cos(x)*sec(x)*tan(x)   \1 + cot (x)/*cos(x)*sec(x)
------------------------------------- + ---------------------------
                cot(x)                               2             
                                                  cot (x)          
sin(x)sec(x)+cos(x)tan(x)sec(x)cot(x)+(cot2(x)+1)cos(x)sec(x)cot2(x)\frac{- \sin{\left(x \right)} \sec{\left(x \right)} + \cos{\left(x \right)} \tan{\left(x \right)} \sec{\left(x \right)}}{\cot{\left(x \right)}} + \frac{\left(\cot^{2}{\left(x \right)} + 1\right) \cos{\left(x \right)} \sec{\left(x \right)}}{\cot^{2}{\left(x \right)}}
Segunda derivada [src]
/                                                       /       2   \                                             /            2   \       \       
|          /         2   \                            2*\1 + cot (x)/*(-cos(x)*tan(x) + sin(x))     /       2   \ |     1 + cot (x)|       |       
|-cos(x) + \1 + 2*tan (x)/*cos(x) - 2*sin(x)*tan(x) - ----------------------------------------- + 2*\1 + cot (x)/*|-1 + -----------|*cos(x)|*sec(x)
|                                                                       cot(x)                                    |          2     |       |       
\                                                                                                                 \       cot (x)  /       /       
---------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       cot(x)                                                                      
(2(cot2(x)+1cot2(x)1)(cot2(x)+1)cos(x)2(sin(x)cos(x)tan(x))(cot2(x)+1)cot(x)+(2tan2(x)+1)cos(x)2sin(x)tan(x)cos(x))sec(x)cot(x)\frac{\left(2 \left(\frac{\cot^{2}{\left(x \right)} + 1}{\cot^{2}{\left(x \right)}} - 1\right) \left(\cot^{2}{\left(x \right)} + 1\right) \cos{\left(x \right)} - \frac{2 \left(\sin{\left(x \right)} - \cos{\left(x \right)} \tan{\left(x \right)}\right) \left(\cot^{2}{\left(x \right)} + 1\right)}{\cot{\left(x \right)}} + \left(2 \tan^{2}{\left(x \right)} + 1\right) \cos{\left(x \right)} - 2 \sin{\left(x \right)} \tan{\left(x \right)} - \cos{\left(x \right)}\right) \sec{\left(x \right)}}{\cot{\left(x \right)}}
Tercera derivada [src]
/                                                                                                                                                                                                                                                  /            2   \                          \       
|                                                                                                                                                                                                                                    /       2   \ |     1 + cot (x)|                          |       
|                                                                                           /                               2                  3\                                                                                  6*\1 + cot (x)/*|-1 + -----------|*(-cos(x)*tan(x) + sin(x))|       
|              /         2   \                            /         2   \                   |                  /       2   \      /       2   \ |            /       2   \ /  /         2   \                                  \                   |          2     |                          |       
|  -sin(x) + 3*\1 + 2*tan (x)/*sin(x) + 3*cos(x)*tan(x) - \5 + 6*tan (x)/*cos(x)*tan(x)     |         2      5*\1 + cot (x)/    3*\1 + cot (x)/ |          3*\1 + cot (x)/*\- \1 + 2*tan (x)/*cos(x) + 2*sin(x)*tan(x) + cos(x)/                   \       cot (x)  /                          |       
|- ------------------------------------------------------------------------------------ + 2*|2 + 2*cot (x) - ---------------- + ----------------|*cos(x) - --------------------------------------------------------------------- - ------------------------------------------------------------|*sec(x)
|                                         cot(x)                                            |                       2                  4        |                                            2                                                                cot(x)                           |       
\                                                                                           \                    cot (x)            cot (x)     /                                         cot (x)                                                                                              /       
(6(cot2(x)+1cot2(x)1)(sin(x)cos(x)tan(x))(cot2(x)+1)cot(x)3(cot2(x)+1)((2tan2(x)+1)cos(x)+2sin(x)tan(x)+cos(x))cot2(x)3(2tan2(x)+1)sin(x)(6tan2(x)+5)cos(x)tan(x)sin(x)+3cos(x)tan(x)cot(x)+2(3(cot2(x)+1)3cot4(x)5(cot2(x)+1)2cot2(x)+2cot2(x)+2)cos(x))sec(x)\left(- \frac{6 \left(\frac{\cot^{2}{\left(x \right)} + 1}{\cot^{2}{\left(x \right)}} - 1\right) \left(\sin{\left(x \right)} - \cos{\left(x \right)} \tan{\left(x \right)}\right) \left(\cot^{2}{\left(x \right)} + 1\right)}{\cot{\left(x \right)}} - \frac{3 \left(\cot^{2}{\left(x \right)} + 1\right) \left(- \left(2 \tan^{2}{\left(x \right)} + 1\right) \cos{\left(x \right)} + 2 \sin{\left(x \right)} \tan{\left(x \right)} + \cos{\left(x \right)}\right)}{\cot^{2}{\left(x \right)}} - \frac{3 \left(2 \tan^{2}{\left(x \right)} + 1\right) \sin{\left(x \right)} - \left(6 \tan^{2}{\left(x \right)} + 5\right) \cos{\left(x \right)} \tan{\left(x \right)} - \sin{\left(x \right)} + 3 \cos{\left(x \right)} \tan{\left(x \right)}}{\cot{\left(x \right)}} + 2 \left(\frac{3 \left(\cot^{2}{\left(x \right)} + 1\right)^{3}}{\cot^{4}{\left(x \right)}} - \frac{5 \left(\cot^{2}{\left(x \right)} + 1\right)^{2}}{\cot^{2}{\left(x \right)}} + 2 \cot^{2}{\left(x \right)} + 2\right) \cos{\left(x \right)}\right) \sec{\left(x \right)}
Gráfico
Derivada de y=cosxsecx/cotx