1 / | | atan(a*x) dx | / 0
1 / 0 for a = 0 / | | | / 2\ | atan(a*x) dx = < log\1 + a / | |- ----------- + atan(a) otherwise / | 2*a 0 \
// 0 for a = 0\ || | / || / 2 2\ | | || log\1 + a *x / | | atan(a*x) dx = C + |<- -------------- + a*x*atan(a*x) | | || 2 | / ||-------------------------------- otherwise| || a | \\ /