Let (x) = 1 + x. (a) Use a graphing calculator to compare the graph of

Let ƒ(x) = √1 + x.
(a) Use a graphing calculator to compare the graph of ƒ with the graphs of the first five Taylor polynomials for ƒ. What do they suggest about the interval of convergence of the Taylor series?
(b) Investigate numerically whether or not the Taylor expansion for ƒ is valid for x = 1 and x = −1.