Title: Fast Trigonometric Functions using the RLIBM Approach Author: Sehyeok Park and Santosh Nagarakatte Abstract: This paper describes our experience developing polynomial approximations for trigonometric functions that produce correctly rounded results for multiple representations and rounding modes using the RLIBM approach. A key challenge with trigonometric functions concerns range reduction with π, which reduces a given input in the domain of a 32-bit float to a small domain. Any rounding error in the value of π is amplified during range reduction, which can result in wrong results. We describe our experience implementing fast range reduction techniques that maintain a large number of bits of π both with floating-point and integer computations. The resulting implementations for trigonometric functions are fast and produce correctly rounded results for all inputs for multiple representations up to 32-bits with a single implementation.