# Scientific Functions

The functions described here perform trigonometric and other transcendental calculations. They generally produce floating-point answers correct to the full current precision. The H (Hyperbolic) and I (Inverse) flag keys must be used to get some of these functions from the keyboard.

One miscellanous command is shift-P (calc-pi), which pushes the value of @c{$\pi$} pi (at the current precision) onto the stack. With the Hyperbolic flag, it pushes the value e, the base of natural logarithms. With the Inverse flag, it pushes Euler's constant @c{$\gamma$} gamma (about 0.5772). With both Inverse and Hyperbolic, it pushes the "golden ratio" @c{$\phi$} phi (about 1.618). (At present, Euler's constant is not available to unlimited precision; Calc knows only the first 100 digits.) In Symbolic mode, these commands push the actual variables pi', e', gamma', and phi', respectively, instead of their values; see section Symbolic Mode.

The Q (calc-sqrt) [sqrt] function is described elsewhere; see section Basic Arithmetic. With the Inverse flag [sqr], this command computes the square of the argument.

See section Numeric Prefix Arguments, for a discussion of the effect of numeric prefix arguments on commands in this chapter which do not otherwise interpret a prefix argument.