Free thyroxine (free T4) tests are used to help evaluate thyroid function and diagnose thyroid diseases, including hyperthyroidism and hypothyroidism, usually after discovering that the thyroid stimulating hormone (TSH) level is abnormal. T4 and another hormone called triiodothyronine (T3) are produced by the thyroid gland.
[When the determinant of a matrix is nonzero, linear system it represents is linearly independent]. When the determinant of a matrix is zero, it rows are linearly dependent vectors, and its columns are linearly dependent vectors.
A matrix is singular iff its determinant is 0. For example, there are 10 singular (0,1)-matrices : The following table gives the numbers of singular matrices for certain matrix classes. matrix is singular iff its determinant is 0. For example, there are 10 singular (0,1)-matrices : The following table gives the numbers of singular matrices for certain matrix classes.