Bharat Stage VI (BS-VI) emission norms:
Bharat Stage VI fuel norms from 1 April 2020 nationwide switching India to world's cleanest diesel and petrol. 2023 - Bharat Stage VI Second Phase Fuel norms from 1 April 2023 have only Petrol also called RDE norms with e20 fuels.
The government has established a set of regulations that every automobile industry must follow to control air pollution. Vehicles must comply with these standards. Currently, the vehicles being introduced to the market are Bharat Stage-VI (BS-VI) compliant, a regulation that came into effect on April 1, 2020.
Match the following:
In the following, \( [x] \) denotes the greatest integer less than or equal to \( x \). 
Choose the correct answer from the options given below:
For x < 0:
f(x) = ex + ax
For x ≥ 0:
f(x) = b(x - 1)2