1 ---------------- / 2\ \1 + x /*atan(x)
/ 1 \ -|------- + 2*x| \atan(x) / ----------------- 2 / 2\ \1 + x / *atan(x)
/ 2 \ | 1 4*x 3*x | 2*|-1 + ----------------- + ------ + ----------------| | / 2\ 2 2 / 2\ | \ \1 + x /*atan (x) 1 + x \1 + x /*atan(x)/ ------------------------------------------------------ 2 / 2\ \1 + x / *atan(x)