function det (m00, m01, m10, m11)
{
    return (m00 * m11) - (m01 * m10);
}
Computes the determinant of a 2x2 matrix. Uses standard double-precision arithmetic, so is susceptible to round-off error.

@function det
@private
@since 3.0.0

@param {number} m00 - The [0,0] entry of the matrix.
@param {number} m01 - The [0,1] entry of the matrix.
@param {number} m10 - The [1,0] entry of the matrix.
@param {number} m11 - The [1,1] entry of the matrix.

@return {number} the determinant.