is the horizontal demand curve for a firm in perfectly competitive market structure implies demand is perfectly inelastic?

why??

No, the horizontal demand curve for a firm in a perfectly competitive market structure does not imply that demand is perfectly inelastic.

In a perfectly competitive market, the demand curve facing an individual firm is perfectly elastic, meaning that the firm can sell as much output as it desires at the market price without affecting the price. This is because there are numerous buyers and sellers, each with a negligible market share, and no individual firm has the ability to influence the market price.

In contrast, a perfectly inelastic demand implies that the quantity demanded remains the same regardless of price changes. This scenario is rare and unlikely to occur in a competitive market.