What courses or textbooks to take after the khan academy courses in mathematics?

Question

IT education

Is it worth it after taking courses at khan.academy to further marinate in mathematics of the 17th century using various textbooks and websites, thereby deepening your knowledge, or can you start taking on such topics as the beginning of mathematical analysis, then mathematical analysis, higher algebra, discrete mathematics and probability theory and mat statistics, graph theory and the theory of analysis of algorithms?

Answer 1

I don’t know what better can explain mathematics than khan academy, unless deeper knowledge is needed in a particular section of it