Parametrized Curves] Use a method from the Problem Section on 13.1 to parametrize the curve obtained by intersecting the cylinder x + y = 1 and the saddle surface z = y-x. [Hint: You may find that a double angle formula from trigonometry is helpful.] Sketch the graph of z = z(t) on a piece of paper so that the t-axis takes up one entire edge of the paper. Wrap the paper into a cylinder in such a way that the graph you sketched is the curve of intersection of the cylinder and saddle surface. Include your sketch of the graph of z = z(t) in your homework solutions.