sign(atan(x - 2)) ----------------- 2 1 + (x - 2)
sign(atan(x - 2))/(1 + (x - 2)^2)
sign(atan(-2 + x)) ------------------ 2 5 + x - 4*x
sign(atan(-2 + x))/(5 + x^2 - 4*x)
sign(atan(-2 + x)) ------------------ 2 5 + x - 4*x
sign(atan(-2 + x))/(5 + x^2 - 4*x)
sign(atan(-2 + x)) ------------------ 2 5 + x - 4*x
sign(atan(-2 + x))/(5 + x^2 - 4*x)
sign(atan(x - 2))/(1.0 + 4.0*(-1 + 0.5*x)^2)
sign(atan(x - 2))/(1.0 + 4.0*(-1 + 0.5*x)^2)