Integral of (4-9x)*sin(nx) dx
The solution
The answer (Indefinite)
[src]
// 0 for n = 0\
|| |
/ // 0 for n = 0\ || //sin(n*x) \ | // 0 for n = 0\
| || | || ||-------- for n != 0| | || |
| (4 - 9*x)*sin(n*x) dx = C + 4*|<-cos(n*x) | + 9*|<-|< n | | - 9*x*|<-cos(n*x) |
| ||---------- otherwise| || || | | ||---------- otherwise|
/ \\ n / || \\ x otherwise / | \\ n /
||------------------------- otherwise|
\\ n /
$$\int \left(4 - 9 x\right) \sin{\left(n x \right)}\, dx = C - 9 x \left(\begin{cases} 0 & \text{for}\: n = 0 \\- \frac{\cos{\left(n x \right)}}{n} & \text{otherwise} \end{cases}\right) + 9 \left(\begin{cases} 0 & \text{for}\: n = 0 \\- \frac{\begin{cases} \frac{\sin{\left(n x \right)}}{n} & \text{for}\: n \neq 0 \\x & \text{otherwise} \end{cases}}{n} & \text{otherwise} \end{cases}\right) + 4 \left(\begin{cases} 0 & \text{for}\: n = 0 \\- \frac{\cos{\left(n x \right)}}{n} & \text{otherwise} \end{cases}\right)$$
/4 9*sin(pi*n) 4*cos(pi*n) 9*pi*cos(pi*n)
|- - ----------- - ----------- + -------------- for And(n > -oo, n < oo, n != 0)
|n 2 n n
< n
|
| 0 otherwise
\
$$\begin{cases} - \frac{4 \cos{\left(\pi n \right)}}{n} + \frac{9 \pi \cos{\left(\pi n \right)}}{n} + \frac{4}{n} - \frac{9 \sin{\left(\pi n \right)}}{n^{2}} & \text{for}\: n > -\infty \wedge n < \infty \wedge n \neq 0 \\0 & \text{otherwise} \end{cases}$$
=
/4 9*sin(pi*n) 4*cos(pi*n) 9*pi*cos(pi*n)
|- - ----------- - ----------- + -------------- for And(n > -oo, n < oo, n != 0)
|n 2 n n
< n
|
| 0 otherwise
\
$$\begin{cases} - \frac{4 \cos{\left(\pi n \right)}}{n} + \frac{9 \pi \cos{\left(\pi n \right)}}{n} + \frac{4}{n} - \frac{9 \sin{\left(\pi n \right)}}{n^{2}} & \text{for}\: n > -\infty \wedge n < \infty \wedge n \neq 0 \\0 & \text{otherwise} \end{cases}$$
Piecewise((4/n - 9*sin(pi*n)/n^2 - 4*cos(pi*n)/n + 9*pi*cos(pi*n)/n, (n > -oo)∧(n < oo)∧(Ne(n, 0))), (0, True))
Use the examples entering the upper and lower limits of integration.