There is still active discussion on X about the approximation exp(−x²) ≈ (1 + cos(sin(x) + x))/2 and some are saying this can just be explained by Taylor series: the series for the two sides differ for the first time at the x6 term, so that’s why you get a good approximation. As I wrote […] The post It’s not just Taylor series first appeared on John D. Cook .