If y=f(x) and a function can be found so that x=g(y), then g(y) is said to be the inverse function of f(x). If y is a trigonometrical function of the angle x, say y=sinx, then x is the inverse trigonometrical function of y, written x=arcsiny or sin⁻¹y. Similarly, the other trigonometrical functions form the inverse trigonometrical functions cos⁻¹y, tan⁻¹y, cot⁻¹y, sec⁻¹y, and cosec⁻¹y. Inverse hyperbolic functions are also formed in this way, e.g. arcsinhy or sinh⁻¹y, cosh⁻¹y, and tanh⁻¹y.