Sr Examen

Integral de (x-1)cos(nx) dx

Límites de integración:

interior superior
v

Gráfico:

interior superior

Definida a trozos:

Solución

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

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