You can get the relationship: 1 - x^2 < cos(x)^2 < 1 / (1 + x^2) from ordinary trigonometry, although you can't just do this with nilsquare infinitesimals; yo

You can get the relationship: 1 - x^2 < cos(x)^2 < 1 / (1 + x^2) from ordinary trigonometry, although you can't just do this with nilsquare infinitesimals; you need a more sophisticated setup.