I think off-zero Taylor series along with lookup table should be at least tried....

		charlieyu1 on March 29, 2022 \| parent \| context \| favorite \| on: Implementing Cosine in C from Scratch (2020) I think off-zero Taylor series along with lookup table should be at least tried. You can approximate cos(x+a) using only cos(a) and sin(a) and the series converges really fast

Remez always beats Taylor series.