3. Consider a ray with endpoint e and (unitary) direction u. Consider a sphere with center c and radius r. The equations for the ray and the sphere are: . ray: R(t)-e ut . sphere: S(x) = (x-c)(x-c) = r Any point r on the ray can be found using the real value t >= 0 Any point x that satisfies the sphere equation is on the sphere. Calculate t such that the point in the ray intersects the sphere. Hint: You can use steps and the reasoning that we used for ray-plane intersections