Here's a graphic:

12345-1-2-3-4-512345-1-2-3-4-5[Graphs generated by this script: setBorder(5); initPicture(-5,5,-5,5);axes(1,1,1,1,1);plot("-x^2-2");strokewidth=3;plot(["2*sin(t)","cos(t)"],0,6.3);strokewidth=2;marker="arrow";stroke="blue";line([4,4],[3,2]);marker="none";strokedasharray="5 2";stroke="red";line([-2,1],[-4,2]);]