Integral de x*cos(2*pi*n*x/T) dx
Solución
Respuesta (Indefinida)
[src]
// 2 \
|| x |
|| -- for n = 0|
|| 2 |
/ || | // x for n = 0\
| || // /2*pi*n*x\ \ | || |
| /2*pi*n*x\ || ||-t*cos|--------| | | || /2*pi*n*x\ |
| x*cos|--------| dx = C - |< || \ t / 2*pi*n | | + x*|
$$\int x \cos{\left(\frac{x 2 \pi n}{t} \right)}\, dx = C + x \left(\begin{cases} x & \text{for}\: n = 0 \\\frac{t \sin{\left(\frac{2 \pi n x}{t} \right)}}{2 \pi n} & \text{otherwise} \end{cases}\right) - \begin{cases} \frac{x^{2}}{2} & \text{for}\: n = 0 \\\frac{t \left(\begin{cases} - \frac{t \cos{\left(\frac{2 \pi n x}{t} \right)}}{2 \pi n} & \text{for}\: \frac{2 \pi n}{t} \neq 0 \\0 & \text{otherwise} \end{cases}\right)}{2 \pi n} & \text{otherwise} \end{cases}$$
/ /2*pi*n\ 2 /2*pi*n\
| 2 t*sin|------| t *cos|------|
| t \ t / \ t /
|- -------- + ------------- + -------------- for And(n > -oo, n < oo, n != 0)
< 2 2 2*pi*n 2 2
| 4*pi *n 4*pi *n
|
| 1/2 otherwise
\
$$\begin{cases} \frac{t \sin{\left(\frac{2 \pi n}{t} \right)}}{2 \pi n} + \frac{t^{2} \cos{\left(\frac{2 \pi n}{t} \right)}}{4 \pi^{2} n^{2}} - \frac{t^{2}}{4 \pi^{2} n^{2}} & \text{for}\: n > -\infty \wedge n < \infty \wedge n \neq 0 \\\frac{1}{2} & \text{otherwise} \end{cases}$$
=
/ /2*pi*n\ 2 /2*pi*n\
| 2 t*sin|------| t *cos|------|
| t \ t / \ t /
|- -------- + ------------- + -------------- for And(n > -oo, n < oo, n != 0)
< 2 2 2*pi*n 2 2
| 4*pi *n 4*pi *n
|
| 1/2 otherwise
\
$$\begin{cases} \frac{t \sin{\left(\frac{2 \pi n}{t} \right)}}{2 \pi n} + \frac{t^{2} \cos{\left(\frac{2 \pi n}{t} \right)}}{4 \pi^{2} n^{2}} - \frac{t^{2}}{4 \pi^{2} n^{2}} & \text{for}\: n > -\infty \wedge n < \infty \wedge n \neq 0 \\\frac{1}{2} & \text{otherwise} \end{cases}$$
Piecewise((-t^2/(4*pi^2*n^2) + t*sin(2*pi*n/t)/(2*pi*n) + t^2*cos(2*pi*n/t)/(4*pi^2*n^2), (n > -oo)∧(n < oo)∧(Ne(n, 0))), (1/2, True))
Estos ejemplos se pueden aplicar para introducción de los límites de integración inferior y superior.