Integral de (1/pi)*x^2*cos(nx) dx
Solución
Respuesta (Indefinida)
[src]
// 3 \
|| x |
|| -- for n = 0|
|| 3 |
|| |
||/sin(n*x) x*cos(n*x) |
|||-------- - ---------- for n != 0 |
2*|<| 2 n |
||< n |
||| |
||| 0 otherwise | // x for n = 0\
/ ||\ | 2 || |
| ||---------------------------------- otherwise| x *|
$$\int \frac{x^{2}}{\pi} \cos{\left(n x \right)}\, dx = C + \frac{x^{2} \left(\begin{cases} x & \text{for}\: n = 0 \\\frac{\sin{\left(n x \right)}}{n} & \text{otherwise} \end{cases}\right)}{\pi} - \frac{2 \left(\begin{cases} \frac{x^{3}}{3} & \text{for}\: n = 0 \\\frac{\begin{cases} - \frac{x \cos{\left(n x \right)}}{n} + \frac{\sin{\left(n x \right)}}{n^{2}} & \text{for}\: n \neq 0 \\0 & \text{otherwise} \end{cases}}{n} & \text{otherwise} \end{cases}\right)}{\pi}$$
/ 2
| 2*sin(pi*n) pi *sin(pi*n) 2*pi*cos(pi*n)
|- ----------- + ------------- + --------------
| 3 n 2
| n n
|---------------------------------------------- for And(n > -oo, n < oo, n != 0)
< pi
|
| 2
| pi
| --- otherwise
| 3
\
$$\begin{cases} \frac{\frac{\pi^{2} \sin{\left(\pi n \right)}}{n} + \frac{2 \pi \cos{\left(\pi n \right)}}{n^{2}} - \frac{2 \sin{\left(\pi n \right)}}{n^{3}}}{\pi} & \text{for}\: n > -\infty \wedge n < \infty \wedge n \neq 0 \\\frac{\pi^{2}}{3} & \text{otherwise} \end{cases}$$
=
/ 2
| 2*sin(pi*n) pi *sin(pi*n) 2*pi*cos(pi*n)
|- ----------- + ------------- + --------------
| 3 n 2
| n n
|---------------------------------------------- for And(n > -oo, n < oo, n != 0)
< pi
|
| 2
| pi
| --- otherwise
| 3
\
$$\begin{cases} \frac{\frac{\pi^{2} \sin{\left(\pi n \right)}}{n} + \frac{2 \pi \cos{\left(\pi n \right)}}{n^{2}} - \frac{2 \sin{\left(\pi n \right)}}{n^{3}}}{\pi} & \text{for}\: n > -\infty \wedge n < \infty \wedge n \neq 0 \\\frac{\pi^{2}}{3} & \text{otherwise} \end{cases}$$
Piecewise(((-2*sin(pi*n)/n^3 + pi^2*sin(pi*n)/n + 2*pi*cos(pi*n)/n^2)/pi, (n > -oo)∧(n < oo)∧(Ne(n, 0))), (pi^2/3, True))
Estos ejemplos se pueden aplicar para introducción de los límites de integración inferior y superior.