/ ___\ atan\\/ x /
atan(sqrt(x))
1 --------------- ___ 2*\/ x *(1 + x)
/1 2 \ -|- + -----| \x 1 + x/ --------------- ___ 4*\/ x *(1 + x)
1 3 1 -------- + ---- + ----------- 2 2 2*x*(1 + x) (1 + x) 8*x ----------------------------- ___ \/ x *(1 + x)