import math


def _rotatePoint(angle, x, y):
    """Rotate an X and Y value by an angle

    >>> x = 1.0
    >>> y = 0.0
    >>> _rotatePoint(math.radians(0.0),x,y)
    (1.0, 0.0)

    >>> x = 0.0
    >>> y = 1.0
    >>> _rotatePoint(math.radians(0.0),x,y)
    (0.0, 1.0)

    >>> x = 1.0
    >>> y = 0.0
    >>> _rotatePoint(math.radians(45.0),x,y)
    (0.7071067811865476, 0.7071067811865475)

    >>> x = 5.0
    >>> y = 0.0
    >>> _rotatePoint(math.radians(45.0),x,y)
    (3.5355339059327378, 3.5355339059327373)


    >>> x = 5.0
    >>> y = 0.0
    >>> _rotatePoint(math.radians(0.1),x,y)
    (4.999992384566438, 0.008726641829491543)
    """
    return x*math.cos(angle) - y*math.sin(angle), x*math.sin(angle) + y*math.cos(angle)