Inquiry learning: known a < 0, - 1 < B < 0, try to compare the size of a, AB, AB2

Inquiry learning: known a < 0, - 1 < B < 0, try to compare the size of a, AB, AB2

∵ a < 0, B < 0, ∵ ab > 0, and ∵ - 1 < B < 0, ab > 0, ∵ AB2 < 0