I don't know how to do question (c)

(a) Suppose that or and ,8 are oating point numbers and we compute a by s==1/s- l/(CHi- {1:- i. {5} If the straightforward algorithm were (backward) numerically stable, what would the computed value of a satisfy? Explain why the algorithm is actually not numerically stable. ii. {4} The quantity ,u. computed as equation {1) could have an unnecessarily large can cellation error if Il e: |or|. But we can reformulate the computation. From {1}, we obtain arms) = 0:1an 1 = a-'a. Then s=fim (man. We can use this new expression to compute a. Show this new algorithm is numerically stable. (b) Suppose that A and B are n x n with A and A + B nonsingular, B of rank k, and M is dened by M=A-1(a+s)-l. (2) i. {4} Forming A'l, (A + B)\