Gudermannian function
= Gudermannian function
{wiki=Gudermannian_function}
The Gudermannian function, often denoted as \\(\\text\{gd\}(x)\\), is a mathematical function that relates the circular functions (sine and cosine) to the hyperbolic functions (sinh and cosh) without explicitly using imaginary numbers. It serves as a bridge between trigonometry and hyperbolic geometry.