g(x) = sec(x)
r = 0.8 (slider from -3 to 3, step 0.1)
g' = Derivative(g)
text1: "y = " + g + ""
Prmtrc = CurveCartesian(t + r / (1 + g'(t)^(2))^(0.5), g(t) + g'(t) * r / (1 + g'(t)^(2))^(0.5), t, -15, 15)