Hello Everyone... This is my first post and I would like to tell you my problem seeking your help... I am studying Physics and Mathematics in my own with the help of some pure mathematics professor who offered to give his help to me in parts that I do not understand.. I am already enrolled in a university but for some personal reasons I am studying other fields that I was forced to study or had to study... Generally 95% of my problems in understanding Physics is due to I lack rigorous understanding to mathematical definitions and proofs … that's why I have stopped studying Physics and turned to more math to solve this problem.. My question is which fields of mathematics should I start with to close this gap ? I have heard that discrete mathematics is quite good for building a mathematical base... Others recommended calculus... Hope my English helped in describing my problem... Looking forward to hearing from you soon.