1 / | | / 3 \ | \x - x/*sin(pi*k*x) dx | / -1
Integral((x^3 - x)*sin((pi*k)*x), (x, -1, 1))
// 0 for k = 0\ || | || // 2 \ | || || 2*sin(pi*k*x) x *sin(pi*k*x) 2*x*cos(pi*k*x) | | // 0 for k = 0\ / || ||- ------------- + -------------- + --------------- for k != 0| | || | | || || 3 3 pi*k 2 2 | | // 0 for k = 0\ // 0 for k = 0\ || //sin(pi*k*x) \ | | / 3 \ || || pi *k pi *k | | 3 || | || | || ||----------- for pi*k != 0| | | \x - x/*sin(pi*k*x) dx = C - 3*|<-|< | | + x *|<-cos(pi*k*x) | - x*|<-cos(pi*k*x) | + |<-|< pi*k | | | || || 3 | | ||------------- otherwise| ||------------- otherwise| || || | | / || || x | | \\ pi*k / \\ pi*k / || \\ x otherwise / | || || -- otherwise | | ||------------------------------- otherwise| || || 3 | | \\ pi*k / || \\ / | ||------------------------------------------------------------------- otherwise| \\ pi*k /
/ 12*sin(pi*k) 4*sin(pi*k) 12*cos(pi*k) |- ------------ + ----------- + ------------ for And(k > -oo, k < oo, k != 0) | 4 4 2 2 3 3 < pi *k pi *k pi *k | | 0 otherwise \
=
/ 12*sin(pi*k) 4*sin(pi*k) 12*cos(pi*k) |- ------------ + ----------- + ------------ for And(k > -oo, k < oo, k != 0) | 4 4 2 2 3 3 < pi *k pi *k pi *k | | 0 otherwise \
Piecewise((-12*sin(pi*k)/(pi^4*k^4) + 4*sin(pi*k)/(pi^2*k^2) + 12*cos(pi*k)/(pi^3*k^3), (k > -oo)∧(k < oo)∧(Ne(k, 0))), (0, True))
Estos ejemplos se pueden aplicar para introducción de los límites de integración inferior y superior.