As shown in the figure, in the plane rectangular coordinate system, points A (0), B (3 3,2), (0,2). Moving point D moves from point 0 along OC to end point C at a speed of 1 unit per second, while moving point E moves from point A along AB to end point B at a speed of 2 units per second. Do EF AB at point e, BC at point f, and then DA.

(1) Number of times to find ∠ABC;

(2) When t is what value, ab ∨ df;

(3) Let the area of the quadrilateral AEFD be s 。

(1) Find the functional relationship between S and T;

② If-parabola y=x2+mx passes through the fixed point e, when s

(The picture is slightly embarrassing)