Q:

Trigonometry sin return negative

I made this code in Python
def hitsin(a):
    a = a*57.3
    return math.sin(a)

so whenever i put hitsin(x) the x converted to radian.  I confuse when I put hitsin(90) the answer is not 1 or any number near 1, but negative (it was -0.9971392129043587).  Am I doing it wrong? 
p.s: I also try to write the same kind of code in C
#include <stdio.h>
#include <math.h>

int main(){
    float degree;
    float result;

    degree = 90;
    degree = degree*57.3;
    result  = cos(result);

    printf("%f",result);

    return 1;
}

But the answer is same. 
sincerely yours
Giri

A:

You should divide by 180/pi, not multiply.   In Python, you can also use math.radians() for the conversion from degree to radians:
def hitsin(a):
    return math.sin(math.radians(a))
hitsin(90)
# 1.0

Furthermore, I doubt the C code gives the same result as the Python code, because it uses cos() instead of sin(). 

A:

You need to divide by 57.3 (or some better approximation to 180/π), not multiply.