Since I was also one of the aspirants prepared for IIT JEE entrance at Resonance, Kota where I built my concept strong over mathematics and one of the biggest reasons for teaching mathematics is that

Devendra Sir, had a great knowledge of chemistry and mathematics, I have been their students for one year in Delhi.
Earlier I had weak concept of thermodynamics and atomic structure.
But Certainly approved him as a good teacher.

Accidentally I found Devendra Sir on this site, But blessed to be a student of them. He focus on deep learning considering all the weak section of student and then boost the fundamental of the student along with how to use the application part in real life