important recurring topics of Quants?

I’m currently going through Schweser and BT videos for Quants. Schweser is quite easy in understanding and i also noticed that many topics such as use of “Differentiation nd Integration” in problems of Quants is not explained in Schweser.

And BT videos are quite old (2012) and syllabus has changed quite alot so m just curious about the important topics for Quants. coz Garp Core readings and Schweser are quite different.

So anyone who have and suggestiona nd idea about important topics in Book 2??/