When elasticity is zero, the demand curve is_____________

When the elasticity of demand is zero, the demand curve is said to be perfectly inelastic. This means that a change in price will not cause any change in the quantity demanded. In other words, no matter how much the price changes, the quantity demanded will remain the same. For example, if the price of insulin for diabetes treatment were to double, people who depend on it to survive would have no choice but to continue buying the same amount. This is because they cannot reduce their consumption of insulin, and therefore, the demand for insulin is perfectly inelastic. In terms of the demand curve, a perfectly inelastic demand curve is vertical, meaning that it is a straight line perpendicular to the horizontal axis. This is because, as mentioned earlier, the quantity demanded remains constant regardless of the price. So, when graphed, the demand curve will be a straight vertical line.