Write a function tridiag(a,b,c) to create the following tridiagonal matrix: bi C 0 a b2c2 A= d2b3 C-1 0 b. for vectors a and C of length n - 1 and vector b of length n. Test your function using e.g. tridiag(1:4, 11:15, 21:24). Write a function tridiag(a,b,c) to create the following tridiagonal matrix: bi C 0 a b2c2 A= d2b3 C-1 0 b. for vectors a and C of length n - 1 and vector b of length n. Test your function using e.g. tridiag(1:4, 11:15, 21:24)