Figure 14 shows the level curves of a function (x, y) and a path r(t), traversed in the direction indicated. State whether the derivative d

Figure 14 shows the level curves of a function ƒ(x, y) and a path r(t), traversed in the direction indicated. State whether the derivative d /dt ƒ(r(t)) is positive, negative, or zero at points A–D.

0 + y 4- 0 -4 -4 D A 0 C -20 -10 B 10 20 30 4 too 8 X