I am trying to build a line-following robot with the schematics I found below. I understood that the comparator is used as the logic for the robot and there is no need for a feedback loop for the comparator in the circuit.
Thus, what is the use of R3 and R4(marked with orange arrow) in the circuit?
Disclaimer: I am a beginner and just started learning electronics. Kindly excuse any comments/questions that doesn't make sense to you. They were written/asked based on the brief knowledge that I have acquired along the way, and asking the community here is part of acquiring more of such knowledge. Thank you for your kind advice.