For the curve given by x=t+t1 and y=t−t1 (t=0), answer the following.
(i) Compute dxdy in terms of t.
(ii) Find all value(s) of t for which the tangent has slope −1, under the additional condition that the x-coordinate of the point is positive.
(iii) Determine the corresponding point(s) on the curve and find the equation of the tangent at each such point.