How do I find cos−1(−0.6481) {cos inverse} of MATH function in Objective-C?

Question

Possible Duplicate:
How do I get arctan MATH function in iOS?

How do I find cos−1(−0.6481) {cos inverse} of MATH function in Objective-C?

Answer 1

math.h is available in iPhone.

#import <math.h>

double v = acos(−0.6481);