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
A device that processes light waves (or photons), either to enhance an image for viewing or to analyze and determine its characteristic properties is called an optical instrument (or "optic" for short).