Aditya Raghavan

Find out what range of inputs are valid and don't lead to overflow, add tests for those boundary conditions, and modify sanitize_inputs accordingly.

Currently black_scholes_test.py only verifies call and put options prices. Greeks were verified against online sources, but they should have tests as well.

* Move math helpers (ln, exp, std_normal, std_normal_cdf) into a separate file math_helpers.cairo * Create helper functions in math_helpers.cairo for fixed point math and use them instead of doing it...

Consider optimizing exp and ln and contribute to Cairo's libs so they can be used by others

This change is [](https://reviewable.io/reviews/starkware-libs/cairo-lang/29)