code: public static double toRadians(double x)
      {
          if (Double.isInfinite(x) || x == 0.0) { // Matches +/- 0.0; return correct sign
              return x;
          }
  
          // These are PI/180 split into high and low order bits
          final double facta = 0.01745329052209854;
          final double factb = 1.997844754509471E-9;
  
          double xa = doubleHighPart(x);
          double xb = x - xa;
  
          double result = xb * factb + xb * facta + xa * factb + xa * facta;
          if (result == 0) {
              result = result * x; // ensure correct sign if calculation underflows
          }
          return result;
      }
docs: Convert degrees to radians, with error of less than 0.5 ULP
  @param x angle in degrees
  @return x converted into radians