Sr Examen

Integral de -x*cos(kx) dx

Límites de integración:

interior superior
v

Gráfico:

interior superior

Definida a trozos:

Solución

Ha introducido [src]
  0               
  /               
 |                
 |  -x*cos(k*x) dx
 |                
/                 
-pi               
$$\int\limits_{- \pi}^{0} - x \cos{\left(k x \right)}\, dx$$
Integral((-x)*cos(k*x), (x, -pi, 0))
Respuesta (Indefinida) [src]
                                                   //           2                      \
                                                   ||          x                       |
                                                   ||          --             for k = 0|
                                                   ||          2                       |
  /                       //   x      for k = 0\   ||                                  |
 |                        ||                   |   ||/-cos(k*x)                        |
 | -x*cos(k*x) dx = C - x*|
            
$$\int - x \cos{\left(k x \right)}\, dx = C - x \left(\begin{cases} x & \text{for}\: k = 0 \\\frac{\sin{\left(k x \right)}}{k} & \text{otherwise} \end{cases}\right) + \begin{cases} \frac{x^{2}}{2} & \text{for}\: k = 0 \\\frac{\begin{cases} - \frac{\cos{\left(k x \right)}}{k} & \text{for}\: k \neq 0 \\0 & \text{otherwise} \end{cases}}{k} & \text{otherwise} \end{cases}$$
Respuesta [src]
/  1    cos(pi*k)   pi*sin(pi*k)                                  
|- -- + --------- + ------------  for And(k > -oo, k < oo, k != 0)
|   2        2           k                                        
|  k        k                                                     
<                                                                 
|                2                                                
|              pi                                                 
|              ---                           otherwise            
\               2                                                 
$$\begin{cases} \frac{\pi \sin{\left(\pi k \right)}}{k} + \frac{\cos{\left(\pi k \right)}}{k^{2}} - \frac{1}{k^{2}} & \text{for}\: k > -\infty \wedge k < \infty \wedge k \neq 0 \\\frac{\pi^{2}}{2} & \text{otherwise} \end{cases}$$
=
=
/  1    cos(pi*k)   pi*sin(pi*k)                                  
|- -- + --------- + ------------  for And(k > -oo, k < oo, k != 0)
|   2        2           k                                        
|  k        k                                                     
<                                                                 
|                2                                                
|              pi                                                 
|              ---                           otherwise            
\               2                                                 
$$\begin{cases} \frac{\pi \sin{\left(\pi k \right)}}{k} + \frac{\cos{\left(\pi k \right)}}{k^{2}} - \frac{1}{k^{2}} & \text{for}\: k > -\infty \wedge k < \infty \wedge k \neq 0 \\\frac{\pi^{2}}{2} & \text{otherwise} \end{cases}$$
Piecewise((-1/k^2 + cos(pi*k)/k^2 + pi*sin(pi*k)/k, (k > -oo)∧(k < oo)∧(Ne(k, 0))), (pi^2/2, True))

    Estos ejemplos se pueden aplicar para introducción de los límites de integración inferior y superior.