## ALP Programming Guide and Reference

[prev][next][parent][TOC]

### Notes

There is no restriction on the range of arguments that FPATAN can accept.

The fact that FPATAN takes two arguments and computes the arctangent of their ratio simplifies the calculation of other trigonometric functions. For instance, arcsin(x) (which is the arctangent of x ö û(1-xý)) can be computed using the following sequence of operations: Push x onto the FPU stack; compute û(1-xý) and push the resulting value onto the stack; run FPATAN.