'Override GeometryEntity.scale since Curve is not made up of Points.
Examples
>>> from sympy.geometry.curve import Curve
>>> from sympy import pi
>>> from sympy.abc import x
>>> Curve((x, x), (x, 0, 1)).scale(2)
Curve((2*x, x), (x, 0, 1))'

def scale(self, x=1, y=1, pt=None):

    if pt:
        pt = Point(pt, dim=2)
        return self.translate(*(- pt).args).scale(x, y).translate(*pt.args)
    (fx, fy) = self.functions
    return self.func(((fx * x), (fy * y)), self.limits)
