A demand curve has constant unitary elasticity at every point. Moving down the curve from one point to the next, price falls by 33 percent and quantity rises by 33 percent; at the next step, both change by 25 percent; then by 16 percent. What shape does this curve have?

1. Constant unitary elasticity means each step down the curve changes price and quantity by the same percentage. 2. Even though the percentage changes stay equal, the dollar price drops shrink at each step, from $3 to $1.50 to $0.75. 3. A steeper slope on the left and a flatter slope on the right produces a curved, concave shape rather than a straight line. 4. A horizontal line describes infinite elasticity and a vertical line describes zero elasticity, neither of which fits this description. _Source: OpenStax Principles of Microeconomics for AP Courses (CC BY 4.0), Ch 5 "Elasticity", section 5.2 | Polar Cases of Elasticity and Constant Elasticity_