Integral de (x-1)cos(nx) dx
Solución
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 - |
$$\int \left(x - 1\right) \cos{\left(n x \right)}\, dx = C + x \left(\begin{cases} x & \text{for}\: n = 0 \\\frac{\sin{\left(n x \right)}}{n} & \text{otherwise} \end{cases}\right) - \begin{cases} x & \text{for}\: n = 0 \\\frac{\sin{\left(n x \right)}}{n} & \text{otherwise} \end{cases} - \begin{cases} \frac{x^{2}}{2} & \text{for}\: n = 0 \\\frac{\begin{cases} - \frac{\cos{\left(n x \right)}}{n} & \text{for}\: n \neq 0 \\0 & \text{otherwise} \end{cases}}{n} & \text{otherwise} \end{cases}$$
/ 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.