sin, cos, tan and rounding error

Question

I\'m doing some trigonometry calculations in C/C++ and am running into problems with rounding errors. For example, on my Linux system:

#include 

        

Answer 1

@Josh Kelley - ok serious answer.
In general you should never compare the results of any operation involving floats or doubles with each other.

The only exceptions is assignment.
float a=10.0;
float b=10.0;
then a==b

Otherwise you always have to write some function like bool IsClose(float a,float b, float error) to allow you to check if two numbers are within 'error' of each other.
Remember to also check signs/use fabs - you could have -1.224647e-16