C 13-16 (i) Make a guess at the limit (if it exists) by evaluating the function at the specified x-values. (ii) Confirm your con- clusions about the limit by graphing the function over an ap- propriate interval. (iii) If you have a CAS, then use it to find the limit. [Note: For the trigonometric functions, be sure to put your calculating and graphing utilities in radian mode.] 13. (a) lim x- 1 x-1x3- 1' ; x = 2, 1.5, 1. 1, 1.01, 1.001, 0, 0.5, 0.9, 0.99, 0.999