Sr Examen

Integral de xcos(kx) dx

Límites de integración:

interior superior
v

Gráfico:

interior superior

Definida a trozos:

Solución

Ha introducido [src]
 pi              
  /              
 |               
 |  x*cos(k*x) dx
 |               
/                
0                
$$\int\limits_{0}^{\pi} x \cos{\left(k x \right)}\, dx$$
Integral(x*cos(k*x), (x, 0, pi))
Respuesta (Indefinida) [src]
                       //           2                      \                           
                       ||          x                       |                           
                       ||          --             for k = 0|                           
                       ||          2                       |                           
  /                    ||                                  |     //   x      for k = 0\
 |                     ||/-cos(k*x)                        |     ||                   |
 | x*cos(k*x) dx = C - |<|----------  for k != 0           | + 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.