\arccot(x)=\arctan\left(\dfrac{1}{x}\right), x>0

\arccot(x)= \dfrac{\pi}{2}-\arctan(x)

f(x) = If[x > 0, atan(1 / x)]
g: y = If[x ≤ 0, π / 2 - atan(x)]
h: y = π / 2 - atan(x)
p: y = (-atan(x))