a) The new environmental regulation providing tax incentives for EV purchases will likely increase the demand for Tesla vehicles. By reducing the effective cost of our electric cars for consumers, the regulation shifts the demand curve to the right, as the tax benefits make EVs more attractive compared to petrol cars. This results in a higher quantity of EVs being demanded at the same price point, thus altering the market equilibrium for our vehicles.

b) Technological advancements leading to reduced manufacturing costs can positively influence Tesla's pricing strategy and sales. With more efficient production, we can either lower prices to boost sales, making our cars more affordable and potentially attracting a larger customer base, or maintain current prices while improving profit margins. This would likely lead to an increase in sales volume, as the combination of lower prices and unchanged quality would stimulate more demand. Additionally, if cost savings aren't passed on to consumers through lower prices, they could be invested in marketing or further R&D, supporting future growth and sustainability in the market equilibrium.