l / | | 3 /pi*n*x\ | x *sin|------| dx | \ l / | / 0
Integral(x^3*sin(((pi*n)*x)/l), (x, 0, l))
// 0 for n = 0\ || | || // 3 /pi*n*x\ 2 /pi*n*x\ 2 /pi*n*x\ \ | || || 2*l *sin|------| l*x *sin|------| 2*x*l *cos|------| | | / || || \ l / \ l / \ l / | | // 0 for n = 0\ | || ||- ---------------- + ---------------- + ------------------ for n != 0| | || | | 3 /pi*n*x\ || || 3 3 pi*n 2 2 | | 3 || /pi*n*x\ | | x *sin|------| dx = C - 3*|<-l*|< pi *n pi *n | | + x *|<-l*cos|------| | | \ l / || || | | || \ l / | | || || 3 | | ||--------------- otherwise| / || || x | | \\ pi*n / || || -- otherwise | | || \\ 3 / | ||----------------------------------------------------------------------------- otherwise| \\ pi*n /
/ 4 4 4 4 | l *cos(pi*n) 6*l *sin(pi*n) 3*l *sin(pi*n) 6*l *cos(pi*n) |- ------------ - -------------- + -------------- + -------------- for And(n > -oo, n < oo, n != 0) < pi*n 4 4 2 2 3 3 | pi *n pi *n pi *n | \ 0 otherwise
=
/ 4 4 4 4 | l *cos(pi*n) 6*l *sin(pi*n) 3*l *sin(pi*n) 6*l *cos(pi*n) |- ------------ - -------------- + -------------- + -------------- for And(n > -oo, n < oo, n != 0) < pi*n 4 4 2 2 3 3 | pi *n pi *n pi *n | \ 0 otherwise
Piecewise((-l^4*cos(pi*n)/(pi*n) - 6*l^4*sin(pi*n)/(pi^4*n^4) + 3*l^4*sin(pi*n)/(pi^2*n^2) + 6*l^4*cos(pi*n)/(pi^3*n^3), (n > -oo)∧(n < oo)∧(Ne(n, 0))), (0, True))
Estos ejemplos se pueden aplicar para introducción de los límites de integración inferior y superior.