Could you help me Find intersection between spline and polyfit

Hello everybody, please can somebody help me? I have spline and polynomial curve of degree one. These two curves intersect (I mean spline and polyfit). CAN YOU HELP ME HOW TO FIND POINT OF INTERSECTION (Coordinates)???? Example of my spline and polyfit.

xx1 = start:0.1:end;
yy1 = spline (points(:,1),points(:,2),xx1);
% plot(points(:,1),points(:,2),'bo',xx1,yy1,'b', 'LineWidth', 2);
plot(xx1,yy1,'b', 'LineWidth', 2);

pol11 = polyfit(K1,K2,1);
s11 = start1:0.1:end1;
ss11 = polyval(pol11,s11);
plot(s11,ss11,'r','Linewidth',2)

This is only part of my code. Thanks everybody for any help!!!!!

Answer 1

[John D'Errico]

Use fzero. Or roots, if you have the chops. Note that a polynomial segment is just a cubic. Subtracting the two functions and setting the result to zero must give an intersection.