1. Let f (x) = cos x. Use p5 for f at x 0 = 0 to estimate cos 1. What is the error? 2. Suppose that f is defined in a neighborhood of c and suppose that f ″(c) exists. (a) Show that (b) Give an...

1. Let f (x) = cos x. Use p5 for f at x₀
= 0 to estimate cos 1. What is the error?

2. Suppose that f is defined in a neighborhood of c and suppose that f ″(c) exists.

(a) Show that

(b) Give an example where the limit in part (a) exists but f ″(c) does not Exist