Let A belongsto Rn times n be a matrix that is tridiagonal a

Let A belongsto R^n times n be a matrix that is tridiagonal (a diagonal, a super-diagonal, and a sub-diagonal). What is the cost of solving Ax=b?

Solution

For a large sparse matrix like a tridiagonal matrix with most of entries as 0 we need not store and compute for all the zeroes and only compute for remaining element

The cost for solving Ax=b remains O(nlogn) which is very small for large value of n as compared to O(n^3) for less sparse matrix

Hence the correct answer is Option C