ABL electronic PIC Microcontrollers PIC16 - Manual (Page 293)

mikroC provides a set of standard ANSI C library functions for floating point
math handling.
Note: Functions have been implemented according to the ANSI C standard, but
certain functions have been modified in order to facilitate PIC programming.
acos
asin
atan
atan2
ceil
cos
cosh
exp
fabs
floor
frexp
ldexp
log
log10
modf
pow
sin
sinh
sqrt
tan
tanh
MikroElektronika: Development tools - Books - Compilers
285
page
mikroC - C Compiler for Microchip PIC microcontrollers
mikroC
making it simple...
ANSI C Math Library
Library Routines
Prototype
double acos(double x);
Description Function returns the arc cosine of parameter
x
; that is, the value whose cosine is
x
.
Input parameter
x
must be between -1 and 1 (inclusive). The return value is in radians,
between 0 and pi (inclusive).
acos