Answer
a. Yes. b. Yes.
Work Step by Step
a. Imagine a car moving toward the right with positive velocity. The driver steps on the brake (applying a negative acceleration) and then steps harder (the negative acceleration increases in magnitude). Meanwhile, the car is slowing down the entire time.
b. Imagine a car moving toward the right with positive velocity. The driver steps hard on the gas/throttle (applying a high positive acceleration) and then lets off just a little (the positive acceleration decreases). Meanwhile, the car is speeding up the entire time.
