It covers objects important to almost all areas of mathematics, so from a mathematical point of view it is absolutely essential to learn about the things covered in a calculus course. And of course,...
Because when trying to solve a problem, Algebra, Trigonometry, Arithmetic, Statistics, and Geometry all failed.
Yes. He also had help from one person
The use of "other" in the question implies that some have already been discussed. What those were is not known so the question cannot be answered.
no he didnt because he wanted a life all about his work