import math


def getLineCircleIntersection(line, center, R):
    """ Return the intersection of a line and circle.

    line is a vector (a, c) such as the line equation is y = ax + c.
    center is the coordinate of the center of the circle.
    R is the radius of the circle.
    """

    a, c = line
    xl, yl = center

    A = a**2 + 1
    B = 2*a*(c - yl) - 2*xl
    C = xl**2 + (c - yl)**2 - R**2

    Delta = B**2 - 4*A*C

    x1 = (-B + math.sqrt(Delta)) / (2*A)
    x2 = (-B - math.sqrt(Delta)) / (2*A)
    y1 = a*x1 + c
    y2 = a*x2 + c

    return [x1, x2], [y1, y2]