Formulas for computation of approximate values of some Bessel functions

Formulas are obtained for J 0 (x),J 1 (x),J 2 (x),I 0 (Y),I 1 (y), I 2 (Y), in terms of trigonometric and hyperbolic functions. These give accuracy suitable for many practical purposes for values of x up to about 4, or even higher in one case, and for greater values of y.