The explicit inverse of a tridiagonal matrix
Palmer R. Schlegel · Mathematics of Computation · 1970
The closed form inverse of a tridiagonal matrix, which is a slight generalization of a matrix considered by D. Kershaw ( Math. Comp. , v. 23, 1969, pp. 189–191), is given in this note. If the matrix has integer elements, an integer multiple of the inverse can be computed by integer arithmetic, that is, without machine roundoff error.