SIn function not producing the correct result

functions sin( float x) and cos(float x) etc. producing incorrect result not matching their expected value.

code

 float temp2 = 0;

 float temp1 = 0;

temp1 = cos(3.142/2);//90
temp2 = sin(3.142/2);//90

debugger

temp1 = -8.38861e+006

temp2 = -8.38861e+006